To me, it’s a gorgeous piece. But part of that is that it’s a song celebrating a lifetime of untroubled love that somehow has a sad feel to it, giving its otherwise trite sentiments a certain gravitās. I don’t know why, though. From my one class in music, I recall that songs in minor keys sound sadder than ones in major keys. But I can’t tell by ear whether this is in a minor key. If not, what else explains the effect produced?
Well, for one thing, it’s rather slow, and borrows heavily from the minor key. While slow can sound happy in some contexts, it’s hard to do with the dark vocals of doo wop.