I almost missed this one, but Geoff Berner and Daniel Kahn are playing (I'm guessing in that order) Tuesday night at Eschschloraque, (Rosenthaler Str. 39, 2nd Hinterhof; S Hackescher Markt). The nominal start time is 10pm, which is probably optimistic.

Geoff Berner is an accordionist from Vancouver who writes clever and often political songs in an effort to "drag Klezmer music kicking and screaming back into the bars", and Daniel Kahn (born in Detroit, former New Orleanian, and now local) plays accordion with his band The Painted Bird and sings both traditional and original Klezmer songs in Yiddish and English. The threads about some of their recent shows should give a good idea of what they're about:

Dec. 2007
Jun. 2007
Dec. 2006

Note that Geoff will also be back again April 15 opening for Kaizers Orchestra, in a show not to be missed.