Hello Dermod,

I don`t have any specific gigs at hand, but you might look for bands like Midnight Court, Inish, An Tain, Irish Weavers (not to be mixed up with the irish band with the same name), Eddy & Marty, Robbie and Gueno, Flinkfinger, Max McColgan & Friends, David Cambrin & Friends, Norland Wind, Spirit Level (all Irish),Kelpie (Irish + Scandinavian), Hot String Quintet (Bluegrass & Swing), Colinda (Cajun) and and and ...(apologies to those I forgot to tell).
The nicer Pubs are the Celtic Cottage (has a website with schedule + produced two CDs with local musicians) Markelstrasse in Steglitz, Molly Mallones, Karl-Marx-Strasse in Neukoelln, Music Pub, Nordufer in Wedding, Shannon Apostel-Paulus-Strasse in Schöneberg. There might be an Irish session at the Emerald Isle in Kreuzberg (havent been there for a long time) on Thursday evenings and sommetimes one on Fridays al the Blarney (Methfesselstrasse in Kreuzberg).
If you post the exact dates I might give some more specific recommendations. Since I am not available tomorrow until Sunday, you might have to refresh this thread.
All the best
Ernest