In Beatles' universe, many moved in and out

• Billy Preston was there for the final Beatles public performance
• Right time%2C right place%3A Klaus Voormann got on board in Hamburg
• Bumped Beatle Pete Best eventually resumed his music career with the Pete Best Band

Planet Beatles was orbited by a constellation of friends, advisers and hangers-on, a few of whom went on to make names for themselves, while others vanished from the cultural landscape after the band broke up in 1970. A primer on the key Beatles satellites:

BILLY PRESTON, keyboardist, died in 2006 at 59

Preston was destined for fame. As a teen, he appeared on Nat King Cole's TV show, later joining Little Richard as an organist. On a tour date in Hamburg with the latter, he met The Beatles, which led to his performing on the Get Back sessions in 1969. That yielded The Beatles' filmed, final performance on the roof of Apple in London. After the band broke up, he would tour with George Harrison and Ringo Starr, and he played both the Concert for Bangladesh and the Concert for George. Preston had success with songs such as Nothing From Nothing and appeared on classic Rolling Stones albums, including Sticky Fingers. On the darker side, he pleaded guilty to insurance fraud in 1998 after setting fire to his house in Los Angeles, and he battled drug addiction throughout his life.

GEORGE MARTIN, producer

Although often hailed as the "fifth Beatle," the affable Martin, 88, brushes aside such praise for his contribution to the Beatles canon. Nevertheless he was integral to the group's transition from composers of pop tunes such as Can't Buy Me Love to the surrealist drama of A Day in the Life. Martin continues to dabble behind the recording board, and son Giles has lent a hand on latter-day Beatles projects. He remains close friends with the surviving two Beatles.

DEREK TAYLOR, publicist, died in 1997 at 65

In a story that would be familiar to Jon Landau — who went from writing about up-and-coming musician Bruce Springsteen to running his career — Taylor was a well-regarded British journalist sent to review a Beatles concert in the band's early days. The rave eventually led manager Brian Epstein to hire Taylor as the band's publicist. Although Taylor left The Beatles' employ a few times, he came back into the fold with the creation of Apple Corps, the group's corporation, in 1968. After The Beatles, he became a record-label executive and collaborated with George Harrison on his 1980 autobiography, I Me Mine.

PETE BEST, drummer

Best, 72, has to possess one of the healthiest senses of self-esteem on the planet. The man who would have been a Beatle was invited to sit in on drums in the summer of 1960, just before the lads headed to Hamburg. But two years and many shows later, the band replaced him with Ringo Starr, a bigger local star. Initially bitter about the dismissal, Best eventually reconciled himself with his brush with fame and in 1988 agreed to play drums at a Beatles convention in Liverpool. He later returned to touring with his Pete Best Band.

NEIL ASPINALL, business associate, died in 2008 at 66

School friends with Paul McCartney and George Harrison, Aspinall started as the band's road manager and personal assistant and eventually headed the band's multimedia company, Apple Corps. He was the point man for the company's numerous legal skirmishes with Steve Jobs' Apple for trademark infringement. In the '90s, Aspinall was executive producer of the band's epic visual and sonic autobiography, The Beatles Anthology. Until his death, he continued to advise the surviving Beatles, as well as the estates of Lennon and Harrison on Beatles-related matters.

ALLEN KLEIN, manager, died in 2009 at 77

A controversial figure in the music industry, Klein had clients who included the Rolling Stones and Sam Cooke before being brought into The Beatles' affairs by John Lennon when the group was imploding. (Paul McCartney had preferred the band go with Lee Eastman, his father-in-law, only heightening the tension.) In the post-Beatles era, Klein helped Lennon and Yoko Ono with their experimental 1972 Imagine documentary and George Harrison with his Concert for Bangladesh. But trouble followed Klein: He did two months of jail time for tax evasion in 1979 for failure to report income from sales of promotional records.

ASTRID KIRCHHERR, artist, photographer

An argument in 1960 between Kirchherr and her boyfriend Klaus Voormann sent Voormann into the bars of Hamburg, where he met The Beatles. Kirchherr later fell in love with Beatle Stuart Sutcliffe (a bass player who left the band in 1961), whom she photographed along with his soon-to-be-famous bandmates. The couple were engaged before Sutcliffe died in 1962 from a brain hemorrhage. Kirchherr, 75, served as an adviser on the 1994 Sutcliffe-focused film Backbeat, and opened a photography shop in Hamburg.

KLAUS VOORMANN, artist, musician

Voormann, 75, can trace his charmed life to the good fortune of living in Hamburg when The Beatles came through town in 1960. When the band struck pop gold, they invited their German friend to London, where he drew the cover for Revolver, which won him a Grammy. Voormann, who had picked up the bass guitar, became a member of Manfred Mann, and he later played on sessions with Lou Reed and Carly Simon. Voormann's retirement in 1989 was interrupted by a 2009 solo album that featured a few of his London-era friends, including Paul McCartney, Ringo Starr and Yusuf Islam (the former Cat Stevens).

MAHARISHI MAHESH YOGI, spiritual guru, died in 2008 at 91

The father of transcendental meditation (TM) played a pivotal — if brief — role in The Beatles, offering spiritual guidance to the quartet at a time when they felt there had to be more to existence than screaming fans and pop riches. Early in 1968, the foursome flew to India with wives and girlfriends in tow. The Beatles abruptly broke off their association with the yogi when word spread that he might have made advances on women at the retreat, although George Harrison would remain intrigued by Eastern religions. The Maharishi went on to establish TM centers around the world. Adherents include David Lynch and Ravi Shankar.