Phil Spector, the eccentric and revolutionary music producer who transformed rock music with his “Wall of Sound” method whose later was convicted of murder, has died at age 81.

California state prison officials said he died Saturday of natural causes at a hospital. Spector was convicted of murdering actress Lana Clarkson in 2003 at his castle-like mansion on the edge of Los Angeles. After a trial in 2009, he was given a 19 years-to-life sentence.