Mandolin

 NATIONAL ANTI-BANJO LEAGUE

Q: What do you call someone who hangs out with bluegrass musicians?

A: Banjo Player

Q: How can you tell if a banjo player has perfect pitch?

A: He can trow it into a dumpster without hitting the rim.

Q: Why did the mass murder at the Banjo convention go unsolved?

A: There were no dental records, all the victims had the same DNA, and nobody was reported missing.