Dramatic Genius: LucasArts and iMUSE

When I was 12 years old I received $25 for my birthday from my aunt. With the $5 I had saved from the previous weeks worth of allowance, I had a whopping $30 to blow on something frivolous. I convinced my mother to drive my sister and I to the largest computer store in the city (40 miles away) so I could buy myself a new computer game. After searching through the racks for almost an hour, I gave up – the games I really wanted were over $60, and the games selling for $30 or less looked unappetizing. I had given up and was ready to leave when my sister grabbed a copy of Monkey Island 2: LeChuck’s Revenge off of the shelf and handed it to me: “Buy this one! It has monkeys!” At first glance I wasn’t interested, but the screenshots on the back of the box reminded me a little of my other adventure games like King’s Quest IV and Police Quest II. I reluctantly agreed to allow my sister to chip-in $20 to buy it, and pouted the hour-long ride home as my sister opened the box and pawed through the ‘feelies’ inside. Sitting in the den in front of our 286 I unenthusiastically installed the game, and loaded it up. Within minutes my sister and I were transfixed upon the monitor and practically rolling on the floor laughing at the ridiculous conversations and character expressions. Monkey Island 2 quickly became one of our favorite PC games and was the gateway to a larger world of cinematic adventure games. Within weeks, I convinced my parents to buy me an AdLib sound card for christmas so I could hear the glorious midi music. In this article I look at LucasArts’s seminal iMUSE system – the Interactive Musical Scoring Engine that was used in every LucasArts adventure game from 1991-2000.

Although sound quality in games has improved much since the early 8-bit days, little improvement has been seen in the musical department besides the necessary move to MP3-based soundtracks that simplified the decade-old problem of sound card selection. This article looks at what was (and still is) an innovative and subtle dramatic music system that produced gameplay-integrated musical scores in the LucasArts adventure games. Throughout I will be using video and sound clips from a couple of my favorite games to demonstrate the dramatic qualities. A big thank-you to Michael over at the Brainy Gamer, whose articles and comments never fail to inspire me to write more detailed replies here!

A Few Examples of iMUSE in Action

Note: I’ve intentionally dropped the speech volume on the audio tracks in these video clips so it’s easier to focus on the musical score. You’ll need Flash installed to view the following clips I uploaded to Youtube. The clips have been resized to fit this page, so click on them to see larger versions.

In this scene from The Curse of Monkey Island, Wally – a cartographer-cum-pirate – breaks down under Guybrush’s relentless teasing (“I’m gonna… I’m… gonna…. <sniff>”). As you watch the clip, listen to the way in which the metre and rhythm of the score remains the same, while the melody changes to suit a more upbeat and less sinister atmosphere. The transition, heralded by a few light drum beats, reflects the “lightening up” of the situation after Wally finally stops threatening Guybrush with his revolver. The melody transitions seamlessly and gives me the sense that the silly but desperate situation has resolved for our bumbling hero.

In this scene, Guybrush enters the Voodoo Priestess’s swamp, greeted by Murray the Talking Skull. As Guybrush enters the rotting swamp boat the music transitions from a soft ethereal score to a slightly spookier score with the addition of another wind instrument (anyone know what that instrument is called?). The mood changes again when Guybrush pulls the alligator’s tongue and as the Voodoo Priestess appears she is introduced by the addition of a subtle reggae beat played on the organ. Mixed into the Voodoo Priestess’s beat is a soft trumpet chorus that fades in and out that adds a sense of foreboding to the scene. All of these subtleties are, of course, recognized only at the subconscious level as we play the game but add a fine atmosphere to each scene and help paint the characters in certain musical tones.

In this scene, Guybrush walks into the Barbershop and the music transitions immediately. See if you can pick out the five different themes that are played here as he speaks with each buccaneer hairstylist. The differences are all subtle, and serve to both colour the personalities of each pirate and the player’s expectations. If you want to hear the different audio tracks independently, head on over to iMUSE Island – my thanks to them for noticing the different mixes in the first place!

How does iMUSE Work?

According to the original patent document for iMUSE, the purpose of the system is to produce “aesthetically appropriate and natural” music and sound effects that modify the “texture, mood and character” of scenes in response to “a directing system”. The musical sequence (composed of notes and instruments) that the composer sends to the directing system is marked at crucial musical junction points, ie. at every ‘measure’, marking positions at which the music can branch. The musical sequencer has the ability to jump to any specific point of a composition (unlike most music), thus giving a standard musical score much more flexibility much like the difference between an mp3 file and a cassette tape. Furthermore, as I will demonstrate in the next part, iMUSE was also able to transpose musical arrangements into completely different tunes, giving the melody different tones and moods to suit the scene. The easiest way to imagine iMUSE is to think of a musical version of interactive hypertext – the user can jump around and re-arrange things at her/his whim.

The early versions of iMUSE-based games used “MIDI” tracks. Since midi arrangements are progressions of electronic musical notes, each note could be remixed on-the-fly. In some LucasArts games that use midi, such as Monkey Island 2, all sorts of transforms (tempo, volume, pan, instruments, etc) are applied to the midi sequence in order to achieve some dramatic effect. In this scene, Guybrush joins a spitting contest. As he approaches the ‘spitmeister’, listen as the music detunes and quickly drops out instruments, hailing the entrance of our blundering protagonist. Hey, at least he hocked up a decent loogie this time!In games that use mp3-based musical data, the score is broken up into many constituent musical tracks. Each track, as we saw with the Barbery Coast pirates earlier, are timed identical to each other, so the music engine can seamlessly transition between tracks. While the sound designers lose some flexibility with mp3-based music (because they cannot mix the track note-by-note, instrument-by-instrument, in realtime), they at least can standardize the sound coming out of the speakers on the player’s end because the tracks have been pre-recorded according to their specifications.

Final Thoughts

While the musical feats that the iMUSE technology accomplishes are impressive in themselves, it is clear that all of these examples work not only because of the smooth transitions and/or identical rhythms – they work because the sound designers and composers found the right melodies and rhythms that suited the particular dramatic effect represented in each scene or for each character. iMUSE does not create good arrangements itself, as is evidenced by the occasional failed drama in several games, but rather relies upon the creative composers and designers who use it to craft the right mood for a scene. The subtlety that iMUSE allows for gives players the sense that they’re playing a game, and not simply interacting with a computer. And, when scripted-in with interactive dialogue, art direction, animation, story, and unique characters, the end products are adventure games that capture dramatic moments reminiscent of old radio and television dramas. Add in the rather kooky humor that most LucasArts game writers are known for, and every game beams with a gentle yet compelling story that’s downright enjoyable. Since iMUSE was one of those under-the-hood engines that was meant to work through subtlety, it isn’t surprising that it hasn’t really gotten its due now that it has faded into obscurity. It’s sad that there are so few games that can match the kinds of dramatic achievements that the creators of iMUSE did in their time.

If you’re interested in playing some of the classic LucasArts adventure games, I highly suggest heading on over to the SCUMMVM web site and downloading one of the best open source software projects on the web. SCUMMVM allows you to play all of those great oldies on modern PC’s running Linux, Mac OS X, and Windows.

If you’re looking for LucasArts-composed music to add to your music library, wander over to WorldMaker.net (scroll down to the comments section) and take a look at the suggestions – I can confirm those are all great compositions!

This post is included as part of a Blogs of the Round Table discussion on music in video games. Follow the below drop-down list for other January ’08 Round Table entries. My sincere thanks to Corvus for accepting my rather last-minute entry! The list below links to other blogs who participated in this month’s Round Table – I strongly suggesting visiting them.. these articles are all particularly good reads.