Four Notes

The only thing worse than having a short snippet of music stuck in your head is having a short snippet of music that you can't identify stuck in your head. When that snippet is only four notes long, it's especially maddening.

Since I don't have perfect pitch, I can't even tell you which notes are involved. Let's arbitrarily call the first one C. It's held for a long time: at least six or eight counts. Then there's a B-flat for two counts and an A for one; from there it goes back to another long C.

The phrase repeats, I'm pretty sure, which would make it technically a repeated three-note snippet, but I hear it as four, with the fourth note in common with the first note of the repeat.

Possible identifications highly welcome.