Chicago-based indie rock band The Wiitala Brothers, who recently self-released their debut record Bad Blood, will be playing at 6 p.m. Friday at The Catacombs, 123 E. Diamond St., which is downstairs at Grace @ Calvary Church.Other bands playing will be Fleets, Olympus Mons, and Nathe in Wayne. Admission is $5. Call 724-283-0830.

<B>Organ Artists Series of Pittsburgh,</B> in its 31st year, will host Cameron Carpenter to open the series at 4 p.m. Sunday at St. Bernard Roman Catholic Church in Mount Lebanon. (The date was changed from Friday because it conflicted with the G20 Summit.) A reception with light refreshments will follow the concert. Admission is $12 for adults and $2 for students. Call 412-242-2787.