Quoted from DanQverymuch:
Flyer says "songs" which there haven't been a lot of. Get Schwifty, Terry Flaps, the Bowie-esque song by Fart, what else could there be?
The theme song.. guessing it's probably mostly space techno created by danesi. But other songs that have been on the show:
When rick breaks up with unity:
This song was used when they bury themselves:
this song was used on season 3 preview: