US music producer Phil Spector has died at the age of 81, while serving a prison sentence for murder. Spector, who transformed pop with his 'wall of sound' recordings, worked with the Beatles, the Righteous Brothers and Ike and Tina Turner. In 2009, he was convicted of the 2003 murder of Hollywood actress Lana Clarkson. His death was confirmed by the California Department of Corrections and Rehabilitation. 'California Health Care Facility inmate Phillip Spector was pronounced deceased of natural causes at 6:35 p.m. on Saturday, January 16, 2021, at an outside hospital. His official cause of death will be determined by the medical examiner in the San Joaquin County Sheriff's Office,' it said. Spector produced 20 top 40 hits between 1961 and 1965. His production methods influenced major artists including the Beach Boys and Bruce Springsteen. His life was ultimately blighted by drug and alcohol addiction, and he all but retired from the music scene during the 1980s and 1990s. In February 2003, actress Lana Clarkson was found dead at his house in Alhambra, California with a bullet wound to her head. Clarkson, who was known for her work in the sword-and-sorcery genre and starred in films including Barbarian Queen, had met Spector hours earlier at a nightclub. Spector claimed the shooting happened when Clarkson 'kissed the gun' - but his trial heard from four women who claimed Spector had threatened them with guns in the past when they had spurned his advances. Following an initial mistrial, Spector was convicted of second degree murder and given a sentence of 19 years to life. Harvey Phillip Spector was born in New York in 1939, to Russian-Jewish parents. His father killed himself when Spector was a boy, and his mother moved her family to Los Angeles. He began his career in his teens as a performer, forming a band - the Teddy Bears - with three high school friends. They had a hit single in 1958 with a song that took its title from the wording on his father's gravestone: 'To know him is to love him.' The record went to number one on the Billboard Hot 100, but the group split the following year. Spector founded his own record label, Philles, in 1961. He produced high-profile 1960s girl groups such as Crystals and the Ronettes, including on 1963 hits Be My Baby and Baby I Love You. He also worked on The Righteous Brothers' hits You've Lost That Lovin' Feelin' and Unchained Melody. His signature production technique, the 'Wall of Sound,' involved layering several instruments, including strings, woodwind and brass, to give a lush, orchestral sound. In the early 1970s, Spector collaborated with The Beatles on their final album Let It Be, as well as producing John Lennon's solo album Imagine. As the decade progressed, the much-feted producer became reclusive and disturbing accounts of his behaviour became widespread. Spector is said to have held a gun to singer Leonard Cohen's head during sessions for his album Death of a Ladies' Man. Ronettes lead singer Veronica 'Ronnie' Bennett, who became Spector's second wife and divorced h