Entitled Karen Mason and Friends: Christmas in the City, the festive concerts will boast special guests Liz Callaway, Gregg Edelman and the a cappella octet, The Accidentals. Barry Kleinbort directs the 5 and 8 PM performances, which feature musical direction by Christopher Denny.

Callaway, whose Broadway credits include Baby, Miss Saigon and Cats, will solo on "My Grown Up Christmas Wish" and will then join Mason for duets of "Christmas Time Is Here" and "O' Holy Night"; Edelman — of City of Angels and 1776 fame — and Mason will join voices on "Happy Days" and "Starting Here, Starting Now"; and Mason will blend her sound with the Accidentals on "We Three Kings" and "Silent Night." Concertgoers can also expect to hear Mason's renditions of "River," "The Christmas Song," "We Three Kings," "Santa Claus Is Coming to Town," "Winter Wonderland," "Let It Snow," "I'll Be Home for Christmas," "Not This Christmas," "It'll Be Christmas Before You Know It," "Sweetest of Nights" and "I Eat."

Karen Mason has appeared on Broadway in Mamma Mia!, Sunset Boulevard, Jerome Robbins' Broadway and Torch Song Trilogy. Her Off-Broadway credits include And the World Goes 'Round and Carnival, and she has also been seen on the small screen in "Law & Order" and "As the World Turns." A seven-time MAC Award-winning performer, Mason has charmed audiences at Carnegie Hall, Rainbow & Stars, Davenport's and L.A.'s The Cinegrill. Her solo recordings include "The Sweetest of Nights," "When the Sun Comes Out," "Better Days," "Not So Simply Broadway" and "Christmas! Christmas! Christmas!" Her most recent CD is titled "The Sweetest of Nights."

The Peter Jay Sharp Theatre at Symphony Space is located in Manhattan at 2537 Broadway at 95th Street. Tickets, priced $35-$70 ($30-$60 for Symphony Space members), are available by (212) 864-5400 or by visiting www.symphonyspace.org.