Get onto Ebay
Buy a set of cheap bongo drums, and when he starts, sit next to the adjoining wall and play along with him .....

But play slightly off the beat to keep putting him off his timing.

Kepp doing it until you drive him mad and he stops.

( trying to play a guitar to an out of time drummer will drive the most patient soul mad after less than 30 mins!)
( RadG Drinking Mojitos in the sun, Wed 12 Nov 2008, 9:25, Reply)