S&M² - a must-see celebration of the 20th anniversary of Metallica’s groundbreaking S&M concerts and album recorded with the San Francisco Symphony - hits the big screen on October 9 for one night only in over 3,000 movie theaters around the world.

Ahead of screenings, Lars Ulrich, Kirk Hammett and members of the San Francisco Symphony talked to Rolling Stone about why they collaborated again. In the following excerpt, Ulrich explains how late Metallica bassist Cliff Burton was the band's "gateway" to classical music.

“Cliff was definitely the gateway to a lot of that classical stuff,” Lars says. “When he started talking about classical music in ’83, ’84, James and I weren’t - or at least maybe I, I don’t want to speak for James - we weren’t maybe ready to sort of receive that stuff, but slowly his persistence got things like classical music or Simon and Garfunkel, on our radar. It took a little longer for us to open up.

“But I now see an intersection between some of the darker, more dissonant, and more minor stuff we play,” he continues. “MTT (music director Michael Tilson Thomas) sometimes calls up and says, ‘You gotta check out this performance,’ and he’ll invite me to some stuff like Mahler or Bach or pieces on the darker side. I appreciate a lot of the orchestral stuff but, over the last 20 years, I’ve figured out how to navigate toward the stuff I’m leaning more towards.”

Read more at Rolling Stone.

Get tickets for the S&M² big screen event on October 9 at metallica.film/.