Let’s just get it out of the way right now: There’s no jug-playing in the South Austin Jug Band. And the bluegrass connotation that name carries should be spilled down the drain along with any other moonshine-preconceived notions. Sure, there’s fiddle, mandolin, an upright bass … but there’s also drumming, occasional electric guitar and even digital looping. And Beck. The band’s latest album, Strange Invitation, gets its title from a lyric in Mr. Hansen’s 1997 charmer, “Jackass,” the only cover on this 11-song collection.