This date 27 December 2005 is incorrect. Reruns were being broadcast that week.
Of the guests listed, the band Nada Surf is verified to have been on only in 2008. They were on Craig Ferguson's show on 13 Dec 2005.
The band North Mississippi Allstars can't be verified to have ever been on the Tonight Show. They were on Carson Daly's show on 20 Dec 2005, Conan O'Brien in August 2005, and on Ferguson in 2008.
Mena Suvari was on several times previously in 1999, 2000, and 2001, with different musical guests, not the two above, but nothing later than 2001 can be verified.
It's unusual for there to be two musical guests in one show, so one of these may be erroneous. The identity of this show can't be confirmed as yet.