From Rolling Stone:
Q: Finally, a previously unreleased instrumental song called "Theme," from 1976, surfaced online. What do you remember about that tune?
Chris Frantz: It's kind of a cool song. It was inspired by the Beach Boys. We played it for maybe the first six months that Talking Heads was in existence, and it never got recorded in a proper recording studio. But we do have a studio recording of it from a little basement studio of a friend of ours in the Shirts. We were practicing recording because none of us had done very much recording. So we would go from the Lower East Side over to Brooklyn and we would, thanks to the Shirts, use their little basement studio. We recorded that along with some other things, I recently baked the tapes and transferred them to digital, and they're surprisingly good.
The interview:
http://www.rollingstone.com/music/news/talking-heads-on-stop-making-sense-we-didnt-want-any-bulls-t-20140801The song:
http://youtu.be/Ae_J3iPEE-A