The M+M's Tour was the fifth concert tour by American recording artist Britney Spears. Spears expressed interested to tour again as early as February 2006. She started rehearsing for a show at House of Blues venues in secret, and pulled out of a surprise performance on April 25, 2007, at Los Angeles nightclub Forty Deuce. After a marquee reading "The M+M's" at the House of Blues in San Diego, California, appeared in late April 2007, media sources identified the act as Spears, and the show quickly sold out. The tour began in San Diego and marked the first time Spears performed live since The Onyx Hotel Tour in June 2004.