VIDEO: Glen Hansard Performs 'Falling Slowly' & More on LETTERMAN; Watch Full Concert!

Glen Hansard, composer of Broadway's Tony and Grammy Award-winning Best Musical, Once performed on the "Late Show with David Letterman" and "Live on Letterman" on December 12th. The Oscar winner performed 'When Your Mind's Made Up' and 'Falling Slowly' from the hit Broadway musical along with other original songs.

Watch the fantastic concert in full below!

CBS Interactive's award-winning webcast concert series, "Live on Letterman," will feature Academy Award winning singer-songwriter Glen Hansard performing live from the world-famous Ed Sullivan Theater in New York City and webcast on CBS.com and VEVO, tonight, Dec. 12 (9:00 PM, ET/6:00 PM, PT).

ONCE is based on the 2007 Academy Award-winning film and plays on Broadway at the Bernard B. Jacobs Theatre (242 West 45th Street). The production opened to rave reviews on Sunday, March 18, 2012.

ONCE won eight Tony Awards including Best Musical. The production was also named Best Musical by the New York Drama Critics Circle, Drama Desk, Drama League, Outer Critic Circle and Lucille Lortel Awards.

ONCE is the winner of the 2013 Grammy Award for Best Musical Theater Album.

ONCE features a book by award-winning Irish playwright & screenwriter, Enda Walsh (Penelope, Hunger, The New Electric Ballroom), the Academy Award-winning music and lyrics of Glen Hansard and Markéta Irglová, direction by the acclaimed John Tiffany (Black Watch), movement by Steven Hoggett (Black Watch, American Idiot) and music supervision and orchestrations by Martin Lowe (Mamma Mia!).

The cast of Once features Arthur Darvill as 'Guy' and Joanna Christie as 'Girl.' Also in the company are Adam Wesley Brown, Laurel Griggs, David PatRick Kelly, Jillian Lebling, Katrina Lenk, Brandon McGibbon, Anne L. Nathan, Andy Taylor, Carlos Valdes, Erikka Walsh, Paul Whitty, and J. Michael Zygo.