The cause was cancer, a statement on his Web site said. Mr. Karn announced last year that he had advanced-stage cancer.


Mr. Karn and two friends, David Sylvian and Steve Jansen, formed Japan in 1974. Mr. Karn, who played violin and bassoon at the time, taught himself to play bass and quickly developed an unusual sound and style.


“I wanted to be able to slide and bend notes as I’d learnt to do with the violin, and so decided to take all the frets off the bass guitar,” he explained. “I couldn’t help but feel that bass players were always hidden somewhere in the background, whereas I was determined to be heard.”


Japan disbanded shortly after releasing the hit single “Ghosts” in 1982. Mr. Karn went on to work with the vocalist Peter Murphy, the guitarist David Torn and others. Mick Karn was born Andonis Michaelides in Cyprus and came to Britain with his family when he was 3. He is survived by his wife, Kyoko, and his son, Metis.