A Spy’s Score: A Case Study for No One Lives Forever
Wednesday, July 02, 2003 - 00:27
This article is an excerpt from a paper originally written for the book, DirectX Audio Exposed: Interactive Audio Development, published by Wordware, edited by Todd M. Fay (a.k.a. LAX). [ http://www.wordware.com/ ISBN 1-55622-288-2 ] This excerpt replaces DirectMusic terms with general adaptive audio terms that can be applied to any audio technology. If you're interested in learning about the specific DirectMusic techniques, process, and technology used in No One Lives Forever, read the full length article from the book (due out late summer or early fall 2003) The full length article is much longer than this excerpt and contains detailed information and instruction regarding the DirectMusic production process.
PART I: AN OVERVIEW OF THE SCORENo One Lives Forever (NOLF) is a first person action adventure game. It is a spy story set in the 1960’s, complete with gadgets, gizmos, and guns. The player assumes the role of Cate Archer, British spy extraordinaire! As shooters go, it is refreshingly light hearted and sprinkled with kitsch and humor.
Monolith Productions developed, and Fox Interactive Published No One Lives Forever, for the PC in 2000. I composed and produced the adaptive score, and Rich Ragsdale contributed the title theme. Eric Aho, Nathan Grigg, and Tobin Buttram, created the DirectMusic (DirectX 7) arrangements and composed additional music. Bryan Bouwman programmed and integrated the game’s DirectMusic code and Sonic Network Inc. provided many of the DLS instruments.
For the soundtrack, I was asked to capture the flavor of the 50’s 60’s spy genre, without infringing on any existing copyrights. Believe it or not, at first I was told to limit my use of brass instruments (This directive came to me through the grapevine via the Bond franchise). That is like being asked to produce a blues album without guitars! The powers that be quickly got over the legal paranoia, however. I did have one theme refused because of a subtle P5, m6, M6 melodic progression (made famous by composer John Barry), even though I thought it was the least ‘Bond-ish’ of my themes. Actually, I drew more influence from German composer Peter Thomas, whose film scores have more of the lighthearted feel we were after. The Barbarella soundtrack was also required listening.
I began the pre-production process by writing five or six themes and prototyping them. These themes became the backbone of the adaptive score. The adaptive scoring techniques for NOLF came out of the concepts and technology implemented for three previous Monolith games: Shogo: Mobile Armor Division, Blood II: The Chosen and Sanity. Shogo: Mobile Armor Division was the first game I scored that broke the music down into separate music states, which matched the game action. Blood II: The Chosen and Sanity each added to those concepts, creatively and technically.
NOLF built upon my adaptive scoring foundation, improving on many aspects of my technique. This white paper will describe the adaptive scoring concepts, the production process, and implementation process used to create this game score. I will describe my intentions and the actual outcome; what worked and what didn’t. I will also describe what I’d like to achieve with future action scores.
The Adaptive Concept and Music StatesNOLF gameplay has high points of action and ambient points; times when the pace is furious, and times filled with suspense. In many scenarios the player may direct Cate in with guns blaring or may sneak her through the situation at hand. Obviously the same music cue wouldn’t be appropriate for both approaches. Also, there’s no way of pre-determining how long a firefight might last and what might come immediately after it. These are the reasons that lead me to break the music down into flexible music states.
After writing a thematic idea, I arrange it in a variety of music states using subjective naming conventions that reflects their functionality (or intensity) in the over all score. Some of the tags I’ve employed are ‘ambient’, ‘suspenseful’, ‘action’, etc. Each of these music states can play for an indeterminate amount of time. Typically each music state has about one and a half to three minutes of music composed for it. It is sometimes difficult to calculate the exact amount of time when considering variations. As a general rule, I think in terms of how long a particular music state can hold a listener’s interest (more on this later). A music state can repeat as necessary until another music state is called. I could also define the number of repeats. The music engine supported automatic transitions from one music state to another or even to silence. This prevents the music from repeating ad nauseum for moments when player interaction is limited.
Music SetsEach musical theme in NOLF is arranged using six basic music states that make up a single music set. At the start of a level, one music set is loaded along with the rest of the level assets. The six standard music states are:
- Super ambient
- Action 1
- Action 2
Using variation on just a few instrument tracks of a given music state was very effective and didn’t cut too deeply into the production schedule. Instrument-level variation is used in the lower intensity music states quite often. These music states start differently every time they’re called up, giving the illusion of more music. In some cases a four to eight measure repeating music state feels like three to five minutes of fresh music.
Transitions: Getting from A to B and Back AgainThe ability to transition between the various music states provides the flexibility needed for the soundtrack to adapt to the game state. Seamless musical transitions facilitate this adaptability in a way that sounds intentional and musically satisfying. In NOLF, any of the six music states may be called at any time. This means that any given music state must be able modulate to any of the other five states.
This required transitions between states that made sense musically and which did not interrupt the flow of the score. Sometimes simply starting the next music state on a logical musical boundary was all that was needed. Often, quickly ending one state and starting the next was enough. However, the most satisfying transitions were the ones that built up to a more intense music state or resolved downward to a less intense music state, without missing a beat, so to speak.
The MatrixFirst conceived for the Shogo score, a transition matrix filled the need to keep track of the myriad of possible movement between music states. By defining the matrix in a simple script (more on the script later), I was able to assign short sections of music to act as specific transitions between states. When the game calls for a change of music state, it knows which music state is currently playing, which one it needs to move to and plays the appropriate transition between them.
The transition matrix acts as a look up chart for the music/game engine. With six music states there are thirty possible transitions. Needless to say I didn’t labor over thirty individual sections of music for each theme. Many transitions did not need transition Segments as they sounded good cutting in on an appropriate boundary. Also, I found that the some transition Segments could be used for multiple transitions between music states. Transitions were generally divided into two types, to help clarify my thinking: transitions that move to a higher or more intense music state, and transitions that move to a lower or less intense music state. Categorizing transitions in this way made reusing transition material easier. (i.e. transitioning from music state three to music state two may be similar to ‘3 to 1’, while ‘3 to 4’ may similar to ‘3 to 5’. (But not always!)
Performance BoundariesKey to making the transitions work musically were Performance Boundaries. Performance Boundaries defined the points along a music state where transitions can take place. Boundary types included, ‘immediate’, ‘grid’, ‘beat’, ‘measure’ and ‘segment’. Each of these boundary types proved useful for different situations in NOLF. When a music state was rhythmically ambiguous, immediate or grid worked fine, allowing for the quickest transitions. Beat and Measure boundaries came in handy when the rhythmic pulse needed to stay constant, and Segment boundaries allowed the currently playing melodic phrase or harmony to resolve before transitioning.
Maintaining a balance between coherent musical transitions and the need to move quickly between states, challenged us as arrangers. As you will hear if you play the game, some transitions work better than others do. When a new state is called, there is an acceptable window of time to move to the new state. We used a window of zero to six seconds (eight seconds tops). This meant that at a tempo of 120 BPM, a four-measure phrase (in 4/4) was the absolute maximum that a current music state could finish prior to transitioning to the new state. One typical solution was to use two measure boundaries (for quicker transitions) for most of a music state and four measure boundaries in spots that called for them aesthetically.
Composing and arranging convincing musical transitions in an adaptive score twists your brain and forces you to think non-linearly. The interactive score used in NOLF only scratches the surface in this regard; there is plenty of room for future innovation. I can say for certain that, having written a number of non-linear scores, I’ll never think about music the same way again. In a way, it’s freed my thinking about how music is put together. Even when listening to linear music I sometimes think ‘Hmmm… this piece could just as easily start with this section instead of that one ’or‘ I bet they could’ve started that transition two measures earlier!’ etc. Music is malleable and only is frozen when we record it.
Stinger MotifsTwo or three of the music sets used in NOLF employed Motifs. The Motifs were applied as short musical accents, or stingers that played over the top of the currently playing music state. Performance Boundaries were set so that the Motifs would be in sync with the underlying music, and Chord Tracks were used so that Motifs would play along with a functional harmony (this was the only use of DirectMusic’s difficult to navigate harmonic features).
These Motifs were composed of brass riffs, quick guitar licks, and things that would easily fit over the music state Segments. More flexibility would have been nice so that different Motifs could be assigned to specific music states (possible using DirectX 8 Audio scripting). Five or six Motifs were written for each music set. The engine called a Motif randomly when the player hit an enemy AI square in the head (ouch!). A silent Motif was employed so to prevent a Motif from playing every single time.
Sounds and DLS banksAll the music in NOLF uses Microsoft’s software synthesizer in conjunction DLS. DLS banks are loaded into the software synthesizer (using RAM), and played via the DirectMusic engine. Each music set uses up to 8MB of DLS instruments (as 22kHz samples), which are loaded as each game-level is loaded. These DLS banks are selected, created and optimized for each individual music set. This gives each music set its own timbral character that coincides with the aesthetic needs of each theme.
DirectX 7 didn’t have wave tracks, as DirectX 8 and above does; as a result, premixed tracks weren’t an option. The DLS+MIDI approach provided the flexibility and practicality needed for features such as instrument level variation, and Motifs that respond to harmonic information. My current projects use a combination of wave/streaming tracks and DLS+MIDI tracks. This provides a balance of pre-mixed waves, CD quality with the flexibility of MIDI. However, as processor speeds continue to increase and better real-time DSP comes about, professional production values will be easier to attain via MIDI+DLS. The two approaches will likely merge and simply be two tools in the same toolbox.
Integration and ImplementationEven though we went with an off-the-shelf solution, namely DirectMusic, there was still a good amount of programming needed to successfully integrate the music engine with the LithTech engine (Monolith’s game engine). Thankfully, much of the work was done on previous games, and we simply needed to update the code for NOLF. Perhaps the biggest leap in this area was in how the music states were tied to the game. In Shogo, Blood II, and Sanity, music states were called via location triggers placed strategically throughout the levels. This was a laborious task (done in the LithTech level editor) and was a pain when enemy/NPC placement inevitably changed as the ship date neared. Necessity was the mother-of-invention for NOLF, as we didn’t have the production schedule to individually place music triggers.
Bryan Bouwman and the fabulous programmers at Monolith came up with the bright idea of tying global game-states and NPC-AI directly to music states. This approach made perfect sense as the game knows when there is action on the screen; it knows when Cate is sneaking around in ‘stealth mode’, and it knows when the player is simply exploring a level. To add flexibility, the game-state to music state assignments are done individually for each game level, so different levels could have different assignments. In addition, more than one music state could be assigned to a game-state. For example, music states 5 and 6 were both often assigned to the ‘combat’ game-state and music states 1 and 2 to ‘exploration’, etc. The game chooses randomly between them at runtime. This means that you could play through the same level twice and have a somewhat different score each time, yet the music would be appropriate to the action in both cases.
ScriptingMonolith created a simple scripting method which provided me with some control over the music asset management and implementation. Being a DirectX 7 game we didn’t have the DirectX 8 Audio scripting that now comes with DirectMusic. In NOLF there is a script for each music set, which is called when a game level is loaded. The scripts’ basic functions are:
- Load the music assets for the music set
- DLS instruments
- DirectMusic Styles, Bands, Motifs, and Segments
- Assign DirectMusic segments to the six music states
- Set up the transition matrix
- Assign transition segments
- Assign transition boundaries
- Set the basic reverb settings
- Set up the Motifs and their boundaries
The Test PlayerMonolith also built a handy little LithTech DirectMusic player that contained the adaptive functionality used in the game. It loads a script and its music set, and then plays the various music states using the correct transitions between them (a simple selector allows you to choose music states). Motifs can even be tested over the music states. This player was a lifesaver, as it allowed me to debug the music content in a game like setting before implementing the content.
PART II: THE PRODUCTION PROCESS
The Prototype and Pre-productionThe first step in the whole production process was to zero in on the musical direction and thematic material of the score. This began with discussions about the style of the music with game designer Craig Hubbard. Next, I was to bring these ideas to realization in the studio in the form of a prototype. Each thematic prototype was created in my MIDI studio using all appropriate synthesizer/sampler modules and sounds available. The idea was to ignore the nonlinear aspects that the music would take on, and to ignore the technical limitations the game machine would place on the music. In this way the focus of the prototype was the thematic material itself, the musical style, and an ideal set of production values.
Each prototype was mixed to a stereo wave file and presented to designer and producer. Some themes were accepted on the first take, some were sent back to the drawing-board and others were rejected outright. By the end of the process we had 5 or 6 themes we were all happy with, and full production could begin.
Composing and SequencingThe sequences created for the prototypes (using Digital Performer on a Mac) served as a starting point for production in DirectMusic Producer. Some of the sequences were fairly complete while others required extensive work and additional sections once brought into Producer. From Digital Performer I exported each prototype sequence in the form of a ‘Standard MIDI’ file (.mid). This allowed Producer to import the sequences for editing and arranging.
I did as much sequencing as practical in Digital Performer in conjunction with my samplers. One key piece of advice I can offer when using this approach is to have the instrument samples from your studio match, as closely as possible, the instrument samples of the DLS banks to be used in Producer. This is getting easier to do, as the DLS2 format can be easily translated to GigaStudio (.gig) and SoundFont formats. To create the game score for DieHard: Nakatomi Plaza, I had an exactly mirrored set from DLS as the target format to GigaStudio as the production format.
DLS CreationThe DLS(level 1) instruments for No One Lives Forever came from two sources: First, we licensed many instrument collections from Sonic Network Inc. (The sounds are called SonicImplants. The other samples were home-made, including some solo cello samples. Sounds are a composers palette and having a rich palette, despite memory constraints of the game, was key to making the interactive score convincing.
There are some tricks to creating a rich instrument collection within tough memory requirements.
- Layering sounds and resampling: When creating music in a traditional MIDI studio, layering and stacking instrument patches to create a thick sounding timbre is commonplace. The drawback to this technique in a game is memory usage and limited polyphony. The cure is to layer your patches and resample them into a single set of samples to be assembled into DLS instruments. For example, I created a brass staccato instrument by stacking about 5 or 6 brass patches in unison (including French Horns, trombones, and trumpets). One sample from this instrument using one voice sounded like the entire orchestral brass section playing triple forte!
- The use of unique or interesting sounds: One interesting timbre in a piece of music can carry the piece and make it memorable. The low cello glissando in the ‘H.A.R.M.’ theme is one such example in NOLF. A generic cello patch and the pitch bend wheel would never have cut it. Instead, I brought in cellist Lori Goldston and had her record some short figures, and motifs. The ponticello glissando figures were then sampled and pitched down about a perfect fourth. This became the central figure around which the rest of the piece was composed. One ‘live’ sounding instrument can trick our perception into hearing other parts as performed live.
- Each instrument must sound convincing when soloed: If an instrument sounds weak on its own, it most likely will not add anything to your music. I resampled many instruments with a bit of room or hall reverb on each sample. The real-time reverb in DirectMusic Audiopaths is very useful but it certainly isn’t your Lexicon quality algorithm. Adding a bit of high quality processing o the individual samples, be it reverb, compression, or EQ, can go a long way to get that ‘professional’ sound back into your interactive score.
- The samples should match the individual composition: Even within different orchestral arrangements, different sets of samples are called for depending on the pacing and mood of each piece. The ‘one size fits all’ mentality of General MIDI will fail to give your score anything but a generic quality. Each theme of the NOLF score had some instrument sets that were built specifically for that theme: The vocal ‘BaDeDum’ sample for its theme, the horn ‘blatts’ for the Ambush theme, in addition to the cello samples already mentioned for the H.A.R.M. theme.
Creating looping samples posed a big challenge given the short length of the samples. For many samples, a Mac program called Infinity was used to create internal loops. The program has tools such as cross-fade looping which help smooth out harmonic thumps and clicks common to short loops. That said, short loops are never perfect, and compromises are always made for the sake of memory constraints.
Instrument-level VariationEach instrument part in NOLF can have up to 32 variations. Each time a music state is played, one variation per part is randomly chosen. Multiple variations do not have to be utilized, in fact many instrument parts in NOLF had one “hardwired” variation to play. I found that four or five variations on two or three instrument parts was enough variety for most music states.
The ‘ambient’ and ‘sub-ambient’ states tended to get a deeper variation treatment, with most instrument parts having variations. It may be that the moody, atmospheric, and arrhythmic nature of these music states lent themselves to a truly non-linear treatment.
Variations in the ‘suspense’ or ‘action’ music states entailed two or three parts with variation. This allowed the foundation of that music to remain consistent while providing some variety. There are many instances where instrument-level variation is not used. This was mainly due to a limited production schedule. A simple technique for creating subtle variation is to copy the original track (variation 1), paste it into another variation, and then slightly alter it. The new variation could have the same contour with different embellishments. This way it remains consistent with the intent of the music yet adds interest. Another technique for using variations effectively is composing unique melodies for one pattern’s variations while the other parts may have subtle variation. This technique creates a “lead” instrument that riffs over a consistent, yet changing, bed of music. I ensure that each part has its own rhythmic space to play in. For instance, all of the vibes’ variations may occur during measures three and five, while the flute variations are given measures two and six. This ensures that the parts won’t step on each other, despite its non-linear nature.
Continuous ControllersThe use of continuous controllers is essential to breathing life into any MIDI score. In NOLF, controller 7 (volume) is used to change a part’s general volume, while controller 11 (expression) creates the dynamic ebb and flow. Parts without dynamic expression can sound flat and monotonous, no matter how well the part is written. Inserting expression curves (CC 11), helps convey the dramatic intent of a musical phrase. Expression curves are used in the NOLF score as crescendos, quick swells, fade in/outs, and to emphasize certain phrases of a part.
Creating Transition SegmentsTransitions link the six music states to one another musically. It takes a puzzle-like logic to figure out how the transitions should operate. NOLF uses specifically created Segment files for transitions. The transition matrix architecture, set up in the script, allows specific Segments to be assigned to each possible transition (between 6 music states there are 30 transitions). These transition Segments are one to four measures in length. This duration allows enough time for convincing transitions, while being short enough to keep up with the game action.
I ask myself two basic questions when composing a transition Segment; ‘Which music state am I moving from?’ and ‘To which music state am I transitioning?’ I write down all the possible transitions and methodically check them off as they are created. I begin composing transition Segments to and from silence; in other words, the intos and ends of each music state. The music composed for these intros and ends provide the foundation for other transitions. This is because the material written for a music state’s intro may become the basis for transitioning to that music state from another music states. Also, a music state’s end may also function well when transitioning from that music state to other music states. (This is the puzzle logic I mentioned!) Sometimes I’ll use the end transition of one music state and the intro of another music state as the transition between them. The end material brings the music out of the current music state and the intro brings the music into the next state. More often, this end/intro transition will be the basis for that transition, and further editing and composing is done to make it work well.
Many transition Segments function well in multiple transitions, and this saves production time. For example, the transition Segment built for music states 2 to 3, may also work between music states 2 and 4, etc. I compose one music state’s transitions at a time. Thus, when I’m working on music state 2, I sequentially create transitions between states 2 to 1, 2 to 3, 2 to 4, 2 to 5, and 2 to 6. Again, this is because there are bound to be similarities among these transitions that I can reuse.
Simple transitions are often the most effective. If the music needs to stop or transition quickly, a large percussive accent brings the music to a halt. It’s as if the music hits a wall; blunt and jarring and that frequently works well within the game. There are also cases when no transition Segment is needed between music states. In these cases, the music flows directly from one music state to the next, and the release times of the DLS instruments create a natural blending or cross-fade between music states.
Sometimes, one transition Segment is not adequate for a particular transition. If a music state contains a variety of musical sections, more than one transition Segment may be needed. For instance, music state four has an A section that is 16 measures in length, and a B section also 16 measures long. If the instruments used in each section are different or the harmony and tempo varies between them, then a single end Segment may not work from both section A and section B. In a case such as this, two transition Segments are created; one for transitioning from the A section and a second for transitioning from the B section. During gameplay, the transition matrix calls the appropriate transition Segment depending on the current playback point of the music state.
When creating music states and their transitions, keep their harmonic content in mind. Music states with disparate key centers cause difficult to execute transitions, because the drastic harmonic modulation of the transition may sound unnatural or awkward. I recommend using key centers that are closely related (i.e. CMajor to Gmajor) to create convincing transitions. I also use chromatic modulation in NOLF (i.e. Bmajor to C major), and many transitions simply stay in the same key. It is easy to back yourself into a corner harmonically when creating an adaptive score. Be aware of the tonal centers of the music states as you create them and try to think ahead about how they will transition harmonically.
PART III: INTEGRATION AND IMPLEMENTATION
Integration of TechnologyDirectMusic functionality had already been a part of the LithTech engine, so integration of the technology was already complete. We innovated in the area of AI, however. NOLF already integrated an advanced state machine, which calculates the players state, and enemy AI. The programmers simply made it possible to trigger music states via game states. These game state to music state associations were made in the LithTech level editor so that different game levels could have unique setups if desired. The level editor also allowed two or more music states to be assigned to one game state, one of which would be randomly chosen during run-time. The most intense music states, five and six, were both assigned to the ‘combat’ game state. Also, music states one (silence) and two (sub-ambient), often shared the quiet ‘investigate’ game state. Assigning multiple music states to a single game state cut down the repetition and predictability of music within a given level, by adding variety to game scenarios.
Implementation of the Music ContentThe adaptive music state machine described above, makes implementing the music content easy. The first steps include checking the DirectMusic files into the game and properly setting up each game level. The LithTech level editor selects the music theme and script for a given game level. The music themes are thus assigned to the various levels, each theme being used across an average of three or four levels. Ninety percent of the music’s adaptability is handled by the state machine. Location based triggers account for the other 10 percent, and override the state machine when triggered. Location based triggers come into play when a specific theme or music state is desired regardless of the game state.
NOLF cinematics apply the same themes and music sets as the adaptive game score. Music triggers are placed at key points in a cinematic, where music is needed, and transitions between music states automatically occur. Triggering music states from cinematics works surprisingly well but certainly does not sound as good as custom cinematic scores would have. Music scored specifically to a scene matches the events more precisely than music composed out of context. The adaptive music sets and triggers are used because the NOLF cinematics were not complete in time to score them individually. The lesson is, reserve production time to custom score game cinematics, and demand that the developer finalizes the timing of them before the scoring begins.
CONCLUSIONThe score for No One Lives Forever was a challenge to produce but was also very rewarding. The first challenge was convincing the producers at Fox Interactive that an adaptive score could have high standards of production quality. The Monolith team helped make the case by presenting demos of previous scores, such as Sanity. Also, my prototype themes helped convince them of my abilities as a composer. Putting together convincing DLS banks within tight memory constraints also posed a big challenge. The optimization process was time consuming and tedious, but key to the sound of the game. Final mixing and editing called for great attention to detail by going though all the Patterns -all their variations-, Motifs, and Segments, making sure volume levels, panning, and instrumentation meshed well together. NOLF’s game state/music state integration gave me the greatest reward. It was fantastic to simply drop music into the game and hear the interactivity immediately. It was also gratifying to collaborate with a strong team of arranger/composers. Having the help of three other musicians produced more content for the game, and sharing compositional ideas and techniques made us all better musicians. Finally, spy music was just plain fun to compose. The game’s sense of humor made it a delight to create its music.
Overall, the adaptive design functioned as planned or better. The transitions reacted quickly and smoothly to the game calls, and the mood of each music state matched the on screen action very well. The instrument variation, music state variation, and use of silence, alleviated the repetitiveness common to many games, and the Motifs made direct hits more satisfying to the player. At its best, the adaptive score draws the player deeper into the game experience. My biggest criticism is that sometimes the game states change faster than the music was intended to react. This makes the music seesaw between music states unnaturally. Many of these instances are only noticeable to me, but some are more obvious. I will be thinking of solutions to this type of dilemma for my next adaptive score. Also, the sonic quality of the music is limited due to the 22kHz DLS banks. A combination of wave tracks and DLS banks would have allowed for longer samples, phrases, and premixed sections, which can increase the overall fidelity of a score while maintaining adaptability.
Each adaptive game score I produce gives me ideas and concepts for the next. The biggest lesson learned from NOLF is that global music integration is hugely important to a successful score. Good integration creates the logical lines of communication between the music system and the game engine. If these lines are weak or nonexistent, the music will not respond well to gameplay, no matter how well the music functions out of context. And context is everything.
ADDENDUM: A Guide to the NOLF Media Files
NOLF Quicktime Videos1. EarthOrbit: The Ambush theme starts in music state 5 (combat 1), transitions to music state 2 (ambient), then transitions to music state 6 (combat 2) with motifs.
2. HamburgClub: The BaDeDum theme starts with music state 3 (main theme), transitions to music state 6 (combat 2), the main theme returns then transitions to music state 5 (combat 1), and ends with the dialogue.
3+4. MorroccoAmbushA and MorroccoAmbushB: Each of these movies runs the same scenario but with differing scores. AmbushA transitions to the combat 1 music state, and AmbushB moves to the combat 2 music state.
4. SniperB2: This scene exhibits the Motifs of the Ambush theme well, as the music transitions from music state 2 (sub-ambient) to music state 3 (suspense).
Ambush Music States Audio File Ambush_music_states.mp3This music clip moves through all six of the music states for the Ambush theme.
Time Music State 0:00 6 (combat 2) 1:22 transition 1:30 2 (sub-ambient) 2:14 transition 2:16 4 (suspense) 3:10 transition 3:12 3 (ambient) 4:08 transition 4:12 5 (combat 1) 5:33 transition 4:12 1 (silence)