Philly's next big buzzworthy musical opens this week at the Prince, with deep Philly accents, the Queen of Romania ­– and Mummers. Also new, a nostalgic holiday musical at the Merriam straight outta' the Land of Misfit Toys. Meanwhile, some ongoing shows are outta' here soon. Note the end dates and proceed accordingly.

"The Three Maries"

It's 1926 and Queen Marie of Romania is coming to visit Philadelphia in this new city-centric musical by Michael Ogborn. There are Mummers! Now in previews (opening to be announced). Prince Theater, 1412 Chestnut St., $27-$52, 215 422-4580, princetheater.org.

"Rudolph the Red-Nosed Reindeer: The Musical"

Nostalgic production for those with a place in their hearts for a train with square wheels, based on the classic 1964 Rankin/BassTV special. Merriam Theater, 250 S. Broad St., 7 p.m. Thursday and Friday, and 11 a.m., 2 p.m., and 5:30 p.m. Saturday and next Sunday, $30-$70, 215-893-1999.

"Black Nativity"

This Afrocentric holiday tradition is a joyful, noisy alternative to all those grim Dickensians and cynical elves. Ends Sunday. Theatre Horizon, 401 DeKalb St., Norristown, $22-$49, 610-283-2230.

"Baskerville"

Comedy revisits the Conan Doyle classic, sadly without dreamboat Benedict Cumberbatch as Sherlock but with some good performances. Through Dec. 27. Suzanne Roberts Theatre, 480 S. Broad St., $24-62, 215-985-0420.

"Becoming Dr. Ruth"

This cozy, risk-free biodrama chronicles the life of America's most famous sex therapist. Through Dec. 27. Walnut Street Theatre, 825 Walnut St., $30-$35, 215-574-3550.

"The Book of Mormon"

The enthusiastic elders deliver their religious message in a winning and hilarious, but very much R-rated, song-and-dance package. Through Dec. 27. Forrest Theatre, 1114 Walnut St. Through Sun., Dec. 27. Tickets: $67-$177, 800-447-7400.