♪ On the 11th day...

...of Christmas, my Zombie gave to me: ♪

11 Beastie Boys
10000 Maniacs
9 Female rockers
8 Mile Marshall
7 minute music
6 ft. tall Grace Jones
Ben Folds Fiiiiiive
4/4 time
3 Pips and Gladys
2 Live Crew
and Tom Waits wailing in a treeeeeeee! 

I know, I know, there are only three Beastie Boys, but do you know how obscure the number 11 is in music history?

The Beastie Boys is a three-piece (originally a quartet) hip hip group formed in 1983 out of New York City.  Michael "Mike D" Diamond (drums), Adam "MCA" Yauch (bass, died May 2012) and Adam "Ad-Rock" Horovitz (guitar).  All three provide vocals as well.

"Beastie" is a backronym* for Boys Entering Anarchic States Towards Internal Excellence.  Some of their best-known, game-changing tunes include: Brass Monkey, and Fight For Your Right (to paaaartaaaay!)

*A backronym is an acronym that is created after the fact.  For example: Zebra Orphans Making Boring Inchworm Earrings is a backronym for zombie.