Guitarist Matt Stubbs, longtime guitarist for blues legend Charlie Musselwhite,heads up GA-20, a band that describes itself as a “throwback blues” group. With a focus on story, the melody, and mood, the band draws from traditional country, soul and funk. On tour in support of their forthcoming new album, Crackdown, the band performs tonight at 8:30 at the Beachland Tavern. Tickets cost $15.