Valentine played in Lincoln bands: Montag, Kid Quarkstar, Mondello and Happy Dog. In 2000, Happy Dog changed its name to Square and he moved to Los Angeles from Anaheim, California, where he taught private guitar lessons out of his home. Valentine had also played with Reel Big Fish, firstly when guitarist Aaron Barrett broke his hand and later in 2001, when Barrett fell down some stairs. Valentine displayed a picture from one Reel Big Fish show he played during Maroon 5's appearance on "MTV Cribs". Eventually the members of Square and Kara's Flowers became friends and when Adam Levine, Jesse Carmichael, Mickey Madden and Ryan Dusick began looking for another guitarist, Valentine was approached. The band Kara's Flowers changed their name to Maroon. Personal tensions in Square helped the decision to join the band and shortly afterward, Kara's Flowers became Maroon 5.