Gary Clark Jr. went rooting around in the blues last night on The Tonight Show With Jay Leno with "I'm Numb," from his latest album Blak & Blu. Clark rode a loose, pounding beat as he peeled off the gritty, Beatles-esque riff that powers the song and drawled out the lyrics. Clark's Tonight Show appearance is the latest in a string of high-profile achievements: he performed onstage with the Rolling Stones last December, and just last week won eight times at the Austin Music Awards.