If you spend your weekends banging your head in rock clubs you should give your head a break this time. Metal: A Headbanger's Journey examines heavy metal with an anthropological eye toward sex, death and religion. It's a lot of brain power focused on music that (seemingly) doesn't require much. Talking heads include Rob Zombie, Alice Cooper, Tom Morello and Lemmy. Go see it on Friday night and put what you learn to use Saturday night. The documentary screens Friday and Saturday at midnight at the Inwood Theatre, 5458 Lovers Lane. Admission is $8. Call 214-764-9106 or visit landmarktheatres.com.