Esther de Groot is in a band
An all-girl-punk-goth-type-band by the looks of it.
To further blur the lines of web-comic-fictional-music-critique and the delicious taste of comic artists, here's Jeph Jacques recommended listening and Kean Soo listens to some great music too.
Update: Milford has a Jaguar and just like Paul Frank, three chords. "SPLANG, WONG, CHANG!"