What is Rob Reiner's character name in "This is Spinal Tap"?

Rob Reiner's character in This Is Spinal Tap is Marty Di Bergi, also styled Martin "Marty" Di Bergi. He is the fictional documentary filmmaker narrating and appearing throughout the film.

Di Bergi follows the heavy-metal band Spinal Tap during its troubled American tour, presenting their backstage arguments, missed cues, absurd interviews, and escalating disasters with a supposedly serious filmmaker's perspective. The character's name is also reflected in the film's subtitle: A Rockumentary by Martin Di Bergi.

This Is Spinal Tap was released in 1984 and became famous for its improvised dialogue and deadpan treatment of ridiculous events. Reiner both directed the movie and played Di Bergi, while Christopher Guest, Michael McKean, and Harry Shearer portrayed the band's members. The film helped popularize the modern mockumentary and inspired the phrase about an amplifier going "up to eleven."