Let the David Cook comparisons commence! Long the face of grunge-rock existential despair, one-time Bush frontman Gavin Rossdale has turned to warmer, lovelorn ballads on his “American Idol”-ish new solo album, Wanderlust. Tonight the Gwen Stefani-impregnating rocker does an 8 p.m. show at the Pabst Theater that promises to include many of Bush’s hits.
