We catch up with indie hip-hop’s most hyperarticulate MC during his recent tour with Deerhoof. Busdriver, aka Regan Farquhar, may be known for searing wit and educated prose, but these days he’s all about having fun and playing “for the children.” In this Audiofile, recorded live at San Francisco’s Great American Music Hall, the L.A. know-it-all dryly pinballs between serious and silly, a sober backstage demeanor and high-energy onstage spazzing.