X Japan's Yoshiki: Music saved my life
21 October 2016 Last updated at 00:33 BST
X Japan are one of Japan's most famous heavy metal rock bands.
In the 1980s they helped pioneer the "visual kei" movement associated with brightly coloured hair and flamboyant costumes.
But the band's history has been marked with tragedy, including the death of lead guitarist Hideto Matsumoto in 1998.
Lead songwriter Yoshiki was in London to promote a new documentary, WE ARE X, which is coming out early next year.
He told the BBC his story.
Filmed, produced and edited by Olivia Lang
Footage courtesy of Passion Pictures. WE ARE X is in cinemas March 2017.