Phil Spector has died at 81. The convicted murderer and influential producer, who was known for the “wall of sound” approach in his work, died at an outside hospital according to the California Department Of Corrections. (Per TMZ, Spector contracted COVID-19.) Spector had been serving a prison sentence for the murder of Lana Clarkson after being found guilty of second-degree murder in 2009.

Spector was born on December 26, 1940 in the Bronx. He moved to Los Angeles with his family in 1953 and started in the music industry in 1958 as part of the group the Teddy Bears, who had a chance #1 hit with “To Know Him Is To Love Him.” The Teddy Bears would break up soon after, but Spector became an in-demand songwriter and producer. He co-founded Philles Records and between 1960 and 1965, he had 24 songs in the Top 40 and 13 top-ten singles.

He worked with the Crystals (“He’s A Rebel,” “Uptown,” “Then He Kissed Me,” and “Da Doo Ron Ron”), the Ronettes (“Be My Baby,” “Walking In The Rain”) the Righteous Brothers (“You’ve Lost That Lovin’ Feeling“), and many more. He also produced a Christmas album, A Christmas Gift For You From Philles Records, that included recordings by Darlene Love, the Ronettes, and his other protégées that would become holiday staples. It was during this string of hits that he pioneered his signature “wall of sound” technique, which involved layering all of the instruments on top of each other to build grand and all-encompassing orchestration.

After Ike and Tina Turner’s “River Deep, Mountain High” failed to become an immediate hit in 1966, Spector took a hiatus from music. During this retirement, he married the Ronettes lead single Ronnie Bennett, who would later accuse him of physical and psychological abuse. Spector reportedly kept her locked up inside their house. They divorced in 1974, with Bennett giving up the rights to her music because Spector threatened to hire a hit man to kill her.

Spector re-emerged during the late ’60s to work on music from the late-era British Invasion. He produced the Beatles’ final album Let It Be and oversaw production on a number of solo Beatles albums, including John Lennon’s Plastic Ono Band and Imagine and George Harrison’s All Things Must Pass. Following that string of albums, he sporadically produced albums by the Ramones, Leonard Cohen, and Céline Dion, and reports emerged of him becoming increasingly reclusive and violent.

In 2003, he was arrested after actress Lana Clarkson was found dead from a gunshot wound to the head in his home. Spector was convicted of second-degree murder in 2009. When he died, he was serving a 19-year sentence.