Comtra Theatre, Route 19 in Cranberry Township, presents "A Christmas Carol" through Dec. 20 at the theater on Route 19. "Sweeney Todd" is planned for Jan. 9 to 17. Curtain is at 7:30 p.m. Fridays and Saturdays. 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>"A Musical Christmas Carol" </B>presented by Pittsburgh CLO will be performed through Dec. 21 at the Byham Theater, 101 Sixth St. Tickets range from $26.50 to $44.50 with halfprice tickets available for children ages 3 to 14. Tickets will go on sale Friday. Call 412-456-6666 or visit www.pittsburghCLO.org.<B>City Theatre</B> heralds the return of "Sister's Christmas Catechism," by Maripat Donovan, through Dec. 28 at City Theatre's 252 seat main stage. Kim Richards reprises her role as Sister in an evening filled with laughter and the infamous "Living Nativity" involving audience members. The schedule has shows at 7 p.m. Tuesdays, at 8 p.m. Wednesdays through Fridays, at 2 and 5:30 p.m. Saturdays, and at 2 p.m. Sundays with a special Christmas week schedule at the City Theatre, Bingham and 13th Streets on the South Side. Tickets range from $35 to $60. Call 412-431-2489.<B>"Frost/Nixon,"</B> the 2007 Tony Award-nominated new play by Peter Morgan, will continue through Dec. 28 at the Benedum Center, 719 Liberty Ave. Stacy Keach takes on the role of President Richard Nixon and is joined by British actor Alan Cox as David Frost. Curtain is 7:30 p.m. Tuesdays through Thursdays; at 8 p.m. Fridays; at 2 and 8 p.m. Saturdays; at 1 and 6:30 p.m. Sundays. Tickets range from $20.50 to $54.50 and are available by calling 412-456-6666.<B>Pittsburgh Public Theater</B> brings to life newspaper advice columnist Ann Landers in "The Lady with All the Answers," through Sunday in the O'Reilly Theater, Pittsburgh Public Theater's home at 621 Penn Ave. The curtain goes up at 8 p.m. through Saturday, and at 2 p.m. Saturday and Sunday. Tickets range from $31 to $50; students and those age 26 and younger pay $15.50. Call 412-316-1600 or visit the Web site, www.ppt.org.<B>The Backstage Bar and Cabaret at Theater Square</B>, a project of The Pittsburgh Cultural Trust, in Theater Square at 655 Penn Ave., is staging "I Love You, You're Perfect, Now Change, through Feb. 1, at the CLO Cabaret, 655 Penn Ave. Performances start at 7:30 p.m. Wednesdays through Saturdays, at 2 p.m. Saturdays and Sundays and at 1 p.m. select Thursdays, except some holiday dates in November, December and January. Tickets are $39.50 for evenings or $34.50 for matinees. Call 412-456-6666 or visit the Web site, CLOcabaret.com.

<B>New Castle Playhouse</B>, 202 E. Long Ave. in New Castle, presents the first year of its "A Holiday Memory" show in the Main Theatre, Augustine Auditorium, at 7:30 p.m. Friday and at 2 and 7:30 p.m. Saturday. Tickets are $12 for adults, $10 for senior citizens age 60 and older and students, and $8 for children age 12 and younger. Call the box office at 724-654-3437.