John Tavener, a British composer who recorded for the Beatles' Apple Records, has died. The popular classical musician was 69.

According to The Guardian, which calls Tavener "the single most popular British classical composer of the late 20th and 21st centuries," the artist passed away in his home. In 2007 he suffered a heart attack that almost killed him. He also had Marfan Syndrome, a connective-tissue disorder that caused various health problems over the years.

In the late '60s, Tavener, who was in his twenties at the time, was one of the artists signed by the Beatles to their new Apple Records. The Guardian quoted him as later saying, "I was less surprised at John Lennon's enthusiasm, but I was surprised at Ringo's" -- no doubt spurred by Tavener's decidedly uncommercial appeal. His first record for the label included electronic noise mixed with found sounds.

Even though Tavener, like most of the artists on Apple, didn't last long at the label, he became "the only classical composer of his generation to approach pop-star fame," according to The Guardian. It probably helped that he sported long hair and didn't look too much like other classical-music composers of the era.

In 1997, his composition 'Song for Athene' was performed at Princess Diana's funeral, catapulting him to higher levels of popularity. While his early works were described as "tumultuous, chaotic, modernist and radical" (no wonder Lennon dug him), Tavener later adapted a more spiritual approach to his music.