Rock-music producer Phil Spector has been charged with murdering an actress whose body was found at his home in February.

Spector, known worldwide for the "Wall of Sound" pop style he pioneered in the 1960's, pleaded innocent when he was charged Thursday at a court outside Los Angeles. The 63-year-old defendant has been free on $1 million bail since the woman's death more than nine months ago.

Authorities say Spector shot and killed actress and model Lana Clarkson at his home. The record producer said earlier this year that Ms. Clarkson killed herself.

Spector is credited with changing the sound of pop music with his "Wall of Sound," which used overdubbed vocals, sound effects and orchestral instruments to create a rich, dramatic effect. Many of the 1960's singing groups he worked with, such as the Ronettes, the Crystals and the Righteous Brothers, soared in popularity. Spector also worked with the Beatles on their last album Let It Be in 1970.