Mr. Machover stands at the intersection of composition and computation — he has been a professor of music and media at the Massachusetts Institute of Technology Media Lab since it was founded in 1985 and was the first director of musical research at the contemporary music center founded for Pierre Boulez in Paris. To help organize his library of Philadelphia sounds, he used software developed at M.I.T. called Constellation, which can analyze hundreds of sound files by volume, frequency and shape, then visually display them.

“Philadelphia Voices” is the latest in a series of Machover symphonies inspired by cities. His Detroit piece, “Symphony in D,” featured the sound of a Henry Ford engine. His work about Lucerne, Switzerland, “A Symphony for Lucerne,” evoked the city’s interconnecting water systems, from the nearby Alps to Lake Lucerne to the Reuss River to the fountains that dot the old town.

For Philadelphia he was trying something new: a big choral work with texts written by young poets about democracy, Philadelphia’s innovations, its struggles, the gerrymandering that dilutes the political power of black residents, the city’s block party traditions and its sometimes arcane parking rituals. It was to be sung by more than 200 people from several choirs with ties to the city and its surroundings: the Westminster Symphonic Choir, the Keystone State Boychoir and Pennsylvania Girlchoir, and the Sister Cities Girlchoir.

Mr. Machover was initially unsure about the cheesesteak.

“In each of these cities, I’ve tried to stay away from the kind of obvious: the bagpipe in Edinburgh or the didgeridoo in Australia,” he said. “But if you find those things with the right angle it’s really important. So when I went home and actually listened to the cheesesteak recordings, I realized how very beautiful they were.”

He decided to give the sandwich a solo, accompanied by percussion.

Cheesesteak, Meet Orchestra