A look at iMuse. Two looks in fact.
During development of The Secret of Monkey Island, Michael Land found it impossible to properly synchronize music with the player's actions. After the game was finished, he decided to something about it. Land brought in Peter McConnell and they created iMUSE during development of Monkey Island 2. Clint Bajakian also joined the team to help finish the score of the game in time.
iMUSE uses, like most games of the era, music stored in a MIDI format. The reason for this is that MIDI files just store information on how to play back music, not the music itself. They therefore take up much less space than digital audio recordings, something which was a big concern back in those pre-CD-ROM days.
What separates iMUSE from other MIDI playback engines of the era was that it was capable of dynamic music triggered by the player's actions. It used so-called sysex events saved in the MIDI files themselves to accomplish this. Markers and hooks are two types of these events. A marker was put in a MIDI file when the game's script had to run a particular command when the MIDI player reaches the marker. The command was put in a queue and told to activate once a marker with a certain ID number was encountered. This could be everything from pauses to fadeouts.
A hook, on the other hand, contains not only an ID number, but also what should happen when the hook is encountered. The script would therefore just run a command to listen for a certain hook and then run its command. The hooks are again divided into types, including jumps, transposes, and enabling and disabling instruments.
A MIDI file has the music divided into tracks and the files used by iMUSE are in format 2, which means that each track is a completely separate musical piece. The advantage of this is that the theme playing on a loop in one area can be on track 1 and its endings be on the subsequent tracks. Track 1 can then have jump hooks placed in the right places going to these endings that when played back makes musical sense. If the player leaves the area, iMUSE simply activates one of those hooks and when it is reached, the MIDI player jumps to the right tracks and the music ends properly. A game without iMUSE would typically just end the track abruptly or do fade-out.
Woodtick is one of the areas in Monkey Island 2 where iMUSE really shines. When the player walks around outside, track 1 of a MIDI file is played on a constant loop. The subsequent tracks in that file are segues that make the music slide neatly into the theme of each boat. The last track simply ends the music and is used for when the player enters the map of Scabb Island. Track 1 has a row of identical markers that marks where these segues can be played so that the result sounds nice.
When the player enters a boat, one of the segues (transitions between different musical pieces) is chosen randomly and the markers are activated. The MIDI player then reaches a marker, plays the segue, and then the theme of the boat. Each boat theme has similar segues. The only difference is that they're linked to specific parts of the theme with jump hooks instead of being chosen randomly. When the player then exits the boat, the jump hooks are activated. The hook first reached by the player will cause it to jump to the proper segue, and then we're back to the outside theme.
One additional feature of the outside theme is that it also has 7 starting points that are chosen randomly each time it is started. This makes the music feel less repetitive whenever you leave a boat.
On the boats of Mad Marty and the inn, there's an additional effect. When you enter Mad Marty's boat there is a melody line playing in the right speaker. This can be called Mad Marty's melody. On the left side of the screen are the men of low moral fibre snoring away. When you wake them, the melody line in the right speaker fades down partially and a new one in the left speaker fades up. A bass and snare drum also kick in, changing the tune completely. This is the men of low moral fibre's tune. Because of iMUSE the game can change between these two dynamically whenever the player awakes the men. After they fall asleep, the music changes back to how it was initially.
The Inn does a similar thing by changing the melody line to something resembling Largo's theme whenever you enter his suite.
Wait, there's more!
My first exposure to the Monkey Island series of games was in 1997, when a friend of mine with whom I regularly swapped games lent it to me. Being young, relatively new to adventure games, and somewhat dim at the time of this transaction, I admit that I was a bit skeptical of the title. I remember foolishly thinking [q]It's on floppies! It's got no recorded dialogue! You need a code wheel to even start playing! Just how good can this game be?[/q]
Considering that over 10 years later I'm writing about its goodness for a website whose very name recalls a pivotal game local, I think the answer to that is abundantly clear. I found that the game astounded me on pretty much all fronts even without being flashy (for the time) and audibly verbose. What I'm going to focus on here is what I feel is one of the most evocative parts of that experience, though it's certainly not the only one. What I want to discuss is the amazing soundtrack.
After playing MI2, I went back and played the original Secret of Monkey Island, and though I enjoyed it I must admit that in comparison there was something lacking. I realized pretty quickly that it was something ubiquitous in MI2 that, well, isn't in the first game Ð music. Like a silent movie's accompaniment, MI2's soundtrack follows Guybrush in to every room, characterizing locations, NPCs, and Guybrush's pivotal actions. And like a well-accompanied silent movie, it more than makes up for the fact that you cannot hear the characters speak. The music emphasizes the qualities of every single character in the game, from the laid-back rasta Captain Dread, to the diminutive but surly Largo LaGrande, to the bombastic salesman Stan, to the sinister zombie form of LeChuck himself, each has an evocative theme.
Though Monkey Island 2 is certainly not the only Lucasarts game to make use of the iMuse engine, I firmly believe that the way it uses it is unrivaled by any of its brothers and sisters before or since. To be clear, I'm not just talking about the music itself, but the way it was arranged and fine-tuned to the game experience. Some games I'd played merely cross-faded music as you went from location to location, but in MI2 it was done even more seamlessly. Music actually transitioned in a natural way from one place to another, as though there were a tiny film organist inside your computer playing it.
My favorite example of this is what I like to call the Woodtick variations. In the small makeshift hamlet of Woodtick at the beginning of the game (which, brilliantly, is made up of a bunch of ships pushed together), there is a common motif for the town. Outside, there is a general riff which prevails, but as soon as you enter a specific area of the town (Wally's shop or the tavern, for example) each segues seamlessly into a distinct version of the motif with its own unique melody, and segues right back to the riff as soon as you step out onto the boardwalk. Genius!
Though music technology has changed a lot since MI2 came out, it stands out as one of the best examples of a well-done soundtrack. Other games may have more realistic instrumentation or fancy wav files for each line of dialogue, but LeChuck's Revenge shows that even simple MIDI can provide just as much atmosphere and style if applied brilliantly.
-- Justin 'Spiff' Franklin