This week's free iTunes download, "One Evening," is from Canadian-born singer/songwriter Feist's upcoming debut album Let It Die. Feist wraps sticky-sweet pop production and Brill building-era hooks around early-folk-style storytelling. The result is a fresh and funky neo doo-wop/post-disco sound with spare pop arrangements. "One Evening" tells the tale of an entire relationship that happened over the course of, well, one evening.