I know there was a thread like this before, but I can't find it now.
So who else changes up the music a bit occasionally (muting the game's music and turning on something else in the background)? What songs do you use, and when?
Difficult Encounters (Boss levels, Grinchlin Assault, the Swarm, etc.): Phyrnna - Fallen Blood (4:50 - 8:00)
Winterfest Battles (not including Grinchlin Assault) and Deconstruction Zones: Phyrnna - TPF Trans
Clockwork Tunnels: Phyrnna - Into Combat
Still figuring out music for other areas.
Players say that the game's music is quite good, but I always listen to other music: rock, jazz, baroque, electronica, bluegrass, etc. I don't have specific music for specific levels, though.