Transit Maps Vol. 1
San Francisco BART
The BART transit map was a natural starting place for me, as San Francisco holds a special place in my heart, and has a very simple transit map. The map is mostly pretty linear, so I was able to start by having several trains running side-by side, which made sense for the structure of the piece. Getting my feet wet with this simpler map helped me work with more complex maps in later pieces.
For this piece, a short musical phrase, or cell, was composed for each line. As the train travels down the line, the phrase is re-started every time the train hits a station. The result is that the distance between each station determines how long each cell will play before restarting. This is a bit like re-triggering a sound on a sampler, where the sound file start’s over whenever a button is re-pressed. The phrases for each line were composed in such a way as to minimize conflict between parts no matter how they line up to one another.
In effect, this technique makes the work sound rather like the process-driven music of Steve Reich or Phillip Glass. The percussive and mallet instrumentation chosen for this piece furthers this parallel. The short distance between many of the stations make the piece sound very loop-based, using repeating phrases that interweave with the repeating phrases of other lines. This is also where I learned that to make my transit maps have a more musical structure, I would have to get creative with what lines I used and when. When I tried playing all of the lines at the same time through the piece once, it ended up being a short wall of sound, which was interesting, but not very musical. To remedy this I now have the lines take several passes back and forth across the map; having red yellow and orange head south, then having blue and green head north, so on and so forth until I finally have all instruments playing only on the final pass, giving the piece a sense of buildup and climax.