Known for his big smile and an even bigger afro, Billy Preston died in an avalanche of health, legal and financial problems. It was easy to forget the dizzying talent behind early albums bearing titles like The Wildest Organ in Town and The Most Exciting Organ Ever.

Preston had been unresponsive since the previous November, in fact, when he finally died on June 6, 2006. Recurrent drug problems framed his final days, decades after close collaborations with the Beatles led to a string of solo hits in the '70s and a lengthy stint with the Rolling Stones. At 59, Preston had voluntarily entered rehab, where acute respiratory failure brought on by swelling around his heart pushed him into a coma. A battle over his estate raged for a decade longer.

None of it matched up with Preston's lighthearted public persona. He was specifically invited into the sessions that produced the Beatles' Let It Be in order to keep the peace among the band's warring factions. He appeared on the group's April 1969 single "Get Back," which was credited to "the Beatles with Billy Preston" – a first for a sanctioned band release – as well as its B-side, "Don't Let Me Down." He also played on "I Want You (She's So Heavy)" and "Something" from 1969's Abbey Road. Taking part in the Beatles' 42-minute performance -- their final public performance -- on Jan. 30, 1969, on top of the Apple building in London remained special to him.

"Musically, my favorite moment was on the roof for Let It Be," Preston told the Chicago Sun-Times in 2004. "It was a struggle for them," he added in 2001. "They were kind of despondent. They had lost the joy of doing it all."

The Beatles signed Preston to Apple Records, and George Harrison produced two of his solo albums. He later appeared at Harrison's Concert for Bangladesh, and collaborated on a string of the group's solo projects, including Harrison's All Things Must Pass, Dark Horse, Extra Texture (Read All About It), Thirty Three & 1/3 and Gone Troppo; John Lennon's Plastic Ono Band and Sometime in New York City; and Ringo Starr's Ringo and Goodnight Vienna.

He scored major solo hits with upbeat R&B songs like "Will It Go Round in Circles" and "Nothing from Nothing," along with the synth-driven funk instrumental "Outa-Space," before beginning a lengthy collaboration with the Stones. Preston was part of the sessions for some of the band's most acclaimed albums, including Sticky Fingers, Exile on Main St. and Tattoo You.

He also appeared on Goats Head Soup, It's Only Rock 'n Roll, Black and Blue and various concurrent tours. By 1976, Preston has his own solo spot during Rolling Stones shows. They too eventually drifted apart, but Preston stayed involved with the Stones over the years, appearing on "Saint of Me" from Bridges to Babylon and on Mick Jagger's solo album Wandering Spirit. "Billy was a fantastic and gifted musician – a superb singer in both recording sessions and onstage," Jagger told the Guardian upon Preston's death. "He was great fun to be with, and I will miss him a lot."

Watch Billy Preston Perform 'Don't Let Me Down' With the Beatles

Along the way, Preston was a sideman on Sly and the Family Stone's There's a Riot Goin' On and on Bob Dylan's Blood on the Tracks. He co-wrote "You Are So Beautiful," a hit for Joe Cocker. But legal troubles dogged him into the '90s, as Preston served nine months in a drug rehabilitation center after pleading no contest to cocaine and assault charges in 1992. "I wanted to keep the high that I felt onstage," Preston admitted in an interview with People. "After the crowds go home, you are left alone. Especially when you travel, there is no one there for you."

He was sentenced to prison five years later for violating probation; he pleaded guilty to insurance fraud in an alleged scam in 1998. Preston gamely tried to return to the gospel music of his youth, and later rebounded to work with Eric Clapton (Me and Mr. Johnson), Ray Charles (Genius Loves Company), Neil Diamond (12 Songs) and the Red Hot Chili Peppers (Stadium Arcadium). "[Jail] was a great lesson, an awakening. I needed to reflect, to get rid of some of the dead weight around me," Preston said years later. "You take the bitter with the sweet and I have to say it was my faith that kept me going. I had nothing else to fall back on."

Born William Everett Preston on Sept. 2, 1946, in Houston, he grew up in Los Angeles as a child prodigy. By age 10, he was backing gospel legend Mahalia Jackson. Later, he was given lessons by Charles, worked with Sam Cooke and starred as the young W.C. Handy in the film St. Louis Blues. A 1962 tour of Europe with Little Richard gave Preston the opportunity to meet his boss' opening act, an unknown band called the Beatles.

Preston's connection to the Beatles continued late into his career. He toured with Starr in 1989, performed at 2002's Concert for George, recorded an album called Billy Preston's Beatles Salute in 2004 and appeared with Starr onstage for an anniversary concert honoring the Concert for Bangladesh in 2005.

Still, he died in 2006 after a disputed bankruptcy filing. Preston's surviving friends and family finally reached a tentative agreement over the remains of his fortune in May 2015, eight years after his death. They wouldn't work out the final language for another year. Some $2 million in royalties was split among a bankruptcy trustee and two other groups, Preston Music Group Incorporated and the William Preston Trust. PMGI, which is led by Preston's longtime friend and manager Joyce Moore, received all of his personal items, copyrights and intellectual property.

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