"Musique" was the B-side to the single release of Da Funk. The lyrics of the song are simply the word Musique (French for music) repeated over and over
Because it is a b-side to "Da Funk". It was never intended to be on the album, and in fact, "Da Funk" as a single has sold more units than Homework, so more people own it anyways than they would if it had been on the album. It is basically used to make the single a double-feature.
Elements from the song were used in the track "WDPK 83.7 FM".
This song lends its name to Daft Punk's first compilation album, Musique Vol. 1 (1993-2005), which the song is the opening track to.