Comedy/rock duo Tenacious D -- Jack Black and Kyle Gass -- will headline a Dec. 20 benefit for the United Mitochiondrial Disease Foundation (UMDF) at the House of Blues in Los Angeles. The bill will a

Comedy/rock duo Tenacious D -- Jack Black and Kyle Gass -- will headline a Dec. 20 benefit for the United Mitochiondrial Disease Foundation (UMDF) at the House of Blues in Los Angeles. The bill will also feature as-yet-unannounced special guests.

Tickets -- $50 and $100 -- go on sale at 4 p.m. PT today (Nov. 30) via Ticketmaster Online and Saturday at 2 p.m. PT at Ticketmaster outlets and the House of Blues box office.

The $100 VIP tickets will allow fans to see the show and to attend an after-party with "The D," with hors d'oeuvres and a free commemorative poster; $50 tickets are for the show only.

Mitochondrial diseases result from failures of the mitochondria, specialized compartments present in every cell of the body except red blood cells. Mitochondria are responsible for creating more than 90% of the energy needed by the body to sustain life and support growth. For more information on the UMDF, visit the organization's official Web site.