Trainwreck is led by half of Tenacious D, the preening joke band that uses ’70s rock clichés to strike a balance between better-than-it-should-be musicianship and screaming humor. Trainwreck is Kyle Gass’ baby—he’s best known as the one who isn’t Jack Black—and he joins bandmates in mullet wigs to cover songs like “Footloose” and “Major Tom” and play some originals. Black (a.k.a. Tuffy McFuckalby) has joined the band as a guest performer in the past, as have John C. Reilly (Jerry McCraken) and Tim Robbins (Slim Robbins). Regardless of who's joining Trainwreck onstage, the juvenile sense of humor and scorching guitar riffs remain the same, just replacing the metal spoofing with good-ol'-boy rock in songs about getting blow jobs in sports cars.