Theaterworks USA will perform "Click, Clack, Moo" on Sunday at Seneca Valley Intermediate School, as part of the Pittsburgh International Children's Theater series. Tickets are $9.50 in advance or $11 at the door. Call 412-456-6666 or visit www.phgarts.org.

Comtra Theatre, Route 19 in Cranberry Township, is presenting the musical "My Fair Lady" through Saturday. Curtain is at 7:30 p.m. Friday and Saturday. Admission is $12 for plays and $15 for musicals. Box office opens at 6:45 p.m. the day of the show. Call 724-773-9896.

<B>Pittsburgh Public Theater</B> opens its 35th season with "Ella," the biomusical about Ella Fitzgerald, known as The First Lady of Song. "Ella," which includes 23 hits, runs through Nov. 1 at the O'Reilly Theater, 621 Penn Ave. The show goes on at 8 p.m. Tuesdays through Saturdays (except Oct. 27 when the show will begin at 7 p.m.); at 2 p.m. Saturdays and Sundays; and at 7 p.m. Sundays (but not Nov. 1). Tickets range from $40 to $60; students and those age 26 and younger pay $15. For tickets, call 412-316-1600 or visit www.ppt.org.<B>CLO Cabaret</B> is showing "Forever Plaid" through March 28, at the CLO Cabaret at Theater Square, 655 Penn Ave. "The Plaids" is the story of a 1950s all-male singing group. Tickets are $39.50 for Wednesday, Thursday and Friday evenings, $44.50 for Saturday evenings, and $34.50 for matinees. Call 412-456-6666.REGION<B>New Castle Playhouse</B>, 212 E. Long Ave. in New Castle, opens "I Love You, You're Perfect, Now Change" on Friday and it continues through Nov. 1. Shows start at 7:30 p.m. Fridays and Saturdays and at 2 p.m. Sundays. Tickets are $10. Call 724-654-3437 or visit www.newcastleplayhouse.org.