It's a theme to a secret area. Kinda like The Lost World in DK2. You have to find the secret entrances to this world. Every portal leads to an instrumentalist, and every instrumentalist has an optional side quest for you.
I made it spacey due to the fact that the game is space-orientated. Last minute I found a jazz bass and switched it from the original synth bass.
Right now, I didn't name the instrumentalists, but if you would like to help, here are all the instruments in the song: