Crank the headphones to 11 for this groundbreaking and cult favorite rock mockumentary. As evidenced by the recent sequel, Spinal Tap and its classics like “Stonehenge” and “Big Bottom” endure. There is a bit of melancholy with this film, the directorial debut of the late Rob Reiner, who, along with his wife, Michele, was killed in December. (Reiner also acted in the film.)