We go to Starbucks everyday (even though I don't drink coffee ;)), but don't really pay much attention to what music they have available, other than they do often choose artists (Barenaked Ladies, Sarah McLachlan, Norah Jones) that I tend to like. As for overally ambience, the music, along with the green and brown wood paneling, does add to that especially "branded" experience...
The coffee's passable, but we'd rather go to Illy's or something. Better quality.