"Happy" by Pharrell Williams is one of those songs I'll quickly consider to be an earworm, but not yet; right now, I consider it a personal momento of an old friend who makes me happy - think about this as a "To Whom Are You Drinking Right Now" post.
The accompanying video - 4 minutes long, but repeated over-and-over, lasting *24 hours* in duration - can be found at 24hoursofhappy.com. It's an interesting concept that I don't think is meant for listening until completion (*).
I like that such a cheerful song is performed in the (normally) sad key of F-Minor.
"Happy" will also be released on Williams' second studio album in 2014.
(*) Although ...