Rock at Knoch Battle of the Bands will take place from 5:30 to 11 p.m. Friday at Knoch High School, Saxonburg. The winner will be determined via a voting ticket system. Call 724-352-4385.

<B>Bach Choir of Pittsburgh </B>will present "The Phantom of the Opera (possessive obsession)" at 4 p.m. Sunday, 2 p.m. Nov. 6, and 8 p.m. Nov. 7 at Regent Square Theater, 1035 S. Braddock Ave. Tickets are $25. Call 412-394-3353.<B>Pittsburgh Camerata</B> will present "Tales from the Otherworld" at 8 p.m. Friday at Mount Lebanon United Methodist Church, 3319 W. Liberty Ave. and at 7:30 p.m. Saturday at Sixth Presbyterian Church, 1688 Murray Ave. Tickets for these two shows are $15 for general admission and $5 for full-time students. A performance of this concert at 11 a.m. Saturday at Heinz Memorial Chapel, 1212 Cathedral of Learning, costs $5. Call 412-421-5884 or visit www.pittsburghcamerata.org.