shortest (but steadily growing) list ever

• Brand New, Sainthood Reps, Robbers at the Regency Ballroom September 10, 2011
• Noah and the Whale/Bahamas at the El Rey May 25, 2011
• Eisley/The Narrative/Christie DuPree at the Troubadour May 15, 2011
• Bad Books/Right Away, Great Captain!/Gobotron at the Troubadour January 15, 2011
• fun./Steel Train/ Jarrod Gorbel at The Music Box October 28, 2010
• Mumford & Sons/King Charles/Forgettable Opening Band at the Holloywood Palladium October 19, 2010
• Vampire Weekend/Beach House/The Very Best at Hollywood Bowl September 26, 2010
• Laura Marling at El Rey Theatre July 28, 2010
• Kings of Leon/Built to Spill/The Features at the Hollywood Bowl July 12, 2010
• Good Old War/Yukon Blonde/Audra Mae at the Troubadour June 11, 2010
• Mumford & Sons did a few songs for a radio show. Not sure if this counts as a live performance, though. They played music...live... It counts. (June 3, 2010)
• Manchester Orchestra/The Features/O'Brother/Biffy Clyro at the Troubadour March 9, 2010
• Laura Marling/Pete Roe/The Wheel at The Largo February 4, 2010
• Brand New/Manchester Orchestra/The Builders and the Butchers at the Palladium October 17, 2009
• Brand New at the Troubadour July 18, 2009
• Craig Owens at the Knitting Factory March 26, 2009