Kristin Chenoweth and Christina Applegate to Join Carrie Underwood in Musical TV Special

A Broadway-bound Kristin Chenoweth (she's headed back in spring 2010 in Promises, Promises) and former board-trotter Christina Applegate will join American Idol Carrie Underwood for a '60s-inspired trio on Underwood's televised Carrie Underwood: An All-Star Special. The concert will air December 7 at 8pm EST on Fox.

Also rumored to appear is Dolly Parton, composer of 9 to 5. Parton would join additional guests Brad Paisley and David Cook.

The tentatively titled two-hour special will feature Underwood performing songs from her upcoming album Play On, as well as holiday classics. Additional guest performers are expected to be announced shortly.

Chenoweth is the Tony and Emmy Award-winning Broadway diva of such shows as Wicked, The Apple Tree, You're a Good Man, Charlie Brown and Steel Pier. The actress is also familiar to TV audiences, having stolen scenes on the series as a leading lady on Pushing Daisies and guest star on new hit Glee.

Applegate was a 2005 Tony Award nominee for her Broadway debut in Sweet Charity. The screen vet is best known for her roles on TV's Married...with Children, Jesse and Samantha Who, as well as films including The Sweetest Thing and Anchorman.