Acoustic guitar virtuoso Adrian Legg progs out the Van Dyck on Saturday (7:30 PM, $22, 348-7999). . . . Electronic jazz project Le Rubb will be at the Circus Café Saturday night (10 PM, 583-1106). . . . A majority of Americans now support legal weed. Celebrate Halfway to 420 at Red Square with Flesh-n-Bone of Bone Thugs on Saturday (7:10 PM, 465-0444). . . . Brooklyn experimentalist Ashley Paul (left) will headline an Albany Sonic Arts Collective night at UAG on Sunday (8 PM, 694-3090).