It’s been 15 years since cancer took the life of singer-songwriter George Harrison, the former lead guitarist of the Beatles who would go on to become a successful solo star, and a symbol of spirituality and higher awareness amongst mainstream rockers of his generation. That latter part of his legacy often gets overshadowed by the former; the phenomenon of that group is a well-documented double-edged sword, but nowhere is it more obvious than in the case of “The Quiet One” who famously hated the experience of being in one of the most scrutinized and overhyped musical acts in history.

And in Harrison’s case, being a Beatle made him undoubtedly rich and famous, but he was creatively stifled by the group’s dynamic and the fame that came along with it. And he never got to showcase his all-around skill set within the context of that band.

“I wasn't Lennon or I wasn't McCartney. I was me,” Harrison told BBC-1 interviewer David Wigg in 1969. “And the only reason I started to write songs was because I thought, well if they can write them, I can write them. You know, 'cuz really, everybody can write songs if they want to. If they have a desire to and if they have sort of some musical knowledge and background. And then it's by writing them the same as writing books or writing articles or painting—the more you do it, the better or the more you can understand how to do it. And I used to just write songs. I still do. I just write a song and it just comes out however it wants to. And some of them are catchy songs like ‘Here Comes The Sun’ and some of them aren't, you know. But to me there’s just songs and I just write them and some will be considered as good by maybe the masses and some won’t. But to me they’re just songs, things that are there that have to be got out."

His initial connection with Indian music and culture came via the unfortunate Help!, the Beatles’ tacky 1965 spoof film that featured a storyline about an evil “Indian cult” that was both daftly racist and staggeringly unfunny. Despite that dubious starting point, Harrison’s devotion to the culture and religion would become a hallmark of his life. He’s often praised for introducing western pop audiences to sitar music via his “Indian songs” on Beatles albums, but by 1968, Harrison had decided that he would be better suited to allow the art and culture to speak for itself. He revealed in 1977 that he’d been inspired to put down the sitar after an encounter with Eric Clapton and Jimi Hendrix reignited his passion for the guitar.

“We stopped in New York and checked in a hotel, and Jimi Hendrix and Eric Clapton were both at the same hotel,” Harrison told Crawdaddy magazine, explaining that Clapton would end up giving him a new Les Paul. “And that was the last time I really played the sitar like that.”

Instead, Harrison would produce albums by the Radha Krishna Temple, Ravi Shankar and Ali Akbar Khan. He took Shankar and Khan on tour as his opening act on his ill-fated 1974 Dark Horse tour—a move that was continuously criticized by rock press like Rolling Stone. Harrison’s production talents would become something of a hidden strength at Apple Records; he would produce the underrated Billy Preston albums That’s the Way God Planned It and Encouraging Words and successful releases by Badfinger as well as solo work from Beatles bandmate Ringo Starr. He would play on Badfinger and John Lennon releases—as well as the excellent but now out-of-print Splinter album, The Place I Love, which was released on Harrison’s own Dark Horse imprint. Musically, it was clear that he was capable of much more than just being “the lead guitarist for the Beatles.”

Unlike Lennon and Paul McCartney, whose creativity and cohesion were the fulcrum for the Beatles’ sound and success, Harrison’s full artistry doesn’t really become apparent until the 1970s. While his bursts of ’60s songwriting excellence (“Here Comes the Sun,” “While My Guitar Gently Weeps,” etc.) are undeniable, his genius within that band was primarily limited to providing color for his more celebrated bandmate’s songwriting, such as the simple, plucky riff he gives “And I Love Her” by McCartney, or elevating Lennon’s repetitive “Dear Prudence” with lyrical lead guitar lines. But his solo career reveals the depths of his introspection and the scope of his creativity.

His first solo album, 1970’s All Things Must Pass, is easily his most praised work, and for good reason. Despite Phil Spector’s often-heavy handed production, there is a power in Harrison’s songs and the performances (which feature everyone from Eric Clapton to Billy Preston to Phil Collins doing session work) are epic in the truest sense—no doubt emphasized by Spector’s sonic trademarks. But while the remainder of his catalog doesn’t quite deliver the gigantic returns associated with All Things Must Pass, it’s clear throughout his body of work that he was always a committed songwriter and formidable guitarist.

Living In A Material World wallows in the preachiness that would lead to Harrison falling out of favor with many rock critics, but it’s the most clear-eyed statement of spirituality that he would ever deliver. For it to come at the height of ’70s rock excess says a lot about Harrison’s commitment to following his own moral path, regardless of how “cool” it was for the times. Albums like Dark Horse and Extra Texture were hamstrung affairs (the former by Harrison’s laryngitis and the latter by his divorce from Patty Boyd and general resentment of rock stardom and critics), but Thirty Three 1/3 is an inspired pop album that finds George balancing his ’60s affectations with mid-’70s studio sheen. Both that album and its even stronger follow-up, 1979’s George Harrison, could be dismissed as the former raga rocker going “yacht rock,” but the songwriting is his best since All Things Must Pass and features the best production and session guys (including the legendary Willie Weeks on bass) that Harrison had used since that high-water mark almost a decade earlier.

He admitted that his disdain for the trappings of rock music and the music industry were why he preferred to keep a low profile—even as he made stellar music.

“I still enjoy writing a tune and enjoy in a way making a record,” he said in a 1979 interview with Rolling Stone. “But I hate that whole thing of when you put it out, you become a part of the overall framework of the business. And I was a bit bored with that. If I write a tune and people think it's nice then that's fine by me; but I hate having to compete and promote the thing. I really don't like promotion. In the ’60s we overdosed on that, and then I consciously went out of my way at the end of the ’60s, early ’70s, to try and be a bit more obscure. What you find is that you have a hit and suddenly everybody's knocking on your door and bugging you again. I enjoy being low-profile and having a peaceful sort of life.”

As such, Harrison is still a somewhat mysterious pop culture figure—especially considering he was an alumnus of “That Band.” His successful solo career is largely a footnote to many casual listeners, despite Harrison’s steady chart presence from the early ’70s to the late 1980s. When he died in 2001, his career had been almost completely obscured by the ongoing adulation of the Beatles and his reputation as an elder rock recluse. Harrison was the guy content to live in his castle and work in his garden. He wasn’t a constant presence at award shows like Paul McCartney or on talk shows, a la Ringo Starr. His most recent studio album had been 1987’s Cloud Nine, an unexpectedly successful comeback album that saw him storm the singles charts with the innocuous Rudy Clark cover, “Got My Mind Set On You,” and form the supergroup the Traveling Wilburys with Tom Petty, Bob Dylan, Roy Orbison and ELO’s Jeff Lynne. All of that was largely forgotten—until November 29, 2001.

Harrison’s death led to an outpouring of grief from fans, to widespread reappraisals of his work and to newfound attention on the guitarists’ musical legacy. Contemporary fans recognized that Harrison’s 1972 Concert for Bangladesh was a groundbreaking moment in popular music, the first benefit concert staged by major pop artists. His devotion to Krishna consciousness was given more respect than throughout the cynical 1970s and his role within the Beatles was acknowledged as a driving catalyst for the band as opposed to a peripheral development. Concert for George in 2002 was a high-profile affair, with old friends like McCartney, Clapton, Preston, Petty and Lynne all celebrating the artist the world had overlooked for so long. And Harrison was posthumously inducted into the Rock and Roll Hall of Fame two years later—again celebrated by Petty and Lynne, who would famously share the stage with Prince later that night as The Purple One delivered a transcendent guitar solo on Harrison’s “While My Guitar Gently Weeps.”

Harrison’s music has been reissued successfully and he finally was given a suitable “Best of” compilation with 2009’s Let It Roll: Songs by George Harrison. Because he wasn’t a part of the already-established Lennon-McCartney brand when he began writing songs midway through the Beatles’ career, Harrison has retained control of those songs without the same issues of rate and catalog control that occurred in the wake of the Michael Jackson purchase of ATV in 1985. Now, the Harrison-penned “Here Comes the Sun” is the most popular Beatles track on iTunes and streaming services. One has to think the Quiet One is somewhere getting a chuckle out of that.

From producing movies with his Hand Made Films to playing on Hall & Oates and Belinda Carlisle records, Harrison was awfully busy despite his reputation as a reclusive. And his life and career are full of fascinating missteps like the infamous lawsuit he faced for ripping “My Sweet Lord” from the Chiffons’ “He’s So Fine,” and personal dramas like Clapton falling in love with and eventually marrying Harrison’s first wife Patti Boyd. And there are much darker moments like the 1999 knife attack that left him seriously wounded. It all makes for quite a fascinating story, with the funny, quiet and pensive ex-Beatle at the center. Fifteen years after his death, there’s still a lot to love about George Harrison—and a lot to learn. He remains fascinating in a way that McCartney, with his omnipresence, and Lennon, with his deification, don’t seem to elicit any longer. He’s still classic rock’s best-kept secret.

You get the feeling that he wouldn’t have it any other way.