Martin Leung, The Video Game Pianist formerly known as the Blindfolded Pianist plays the SMB theme song during a Video Games Live! performance in Singapore 2009.

Want some more? Here are a few other performances Martin has done in the past few years.
Martin Leung playing the Super Mario Theme blindfolded at the Games Convention 2007

Martin Leung playing Super Mario Bros theme at Video Games Live London 25 November, 2006:

Check this video out of Martin playing @ the Brady Games booth at E3 2006:

Video Game Live! plays in Sinapore: