Their next studio recording, out in October 69 on Warner Brothers, was called, Then Play On. Kirwin and Green shared writing credits on this release. The Beatles reportedly had considered picking up Fleetwood Mac’s contract for their own Apple Records, but negotiations fell through. In short, Warner offered them more artistic freedom and control than Apple did. Fleetwood Mac stayed with Warner throughout their recording career. The single that preceded Then Play On (but was not included on the album) was Peter Green’s soulful ballad, “Man Of The World” in which the guitar master expressed disillusionment with material success. The tune was autobiographical and prolific, as time soon revealed, and it quickly shot up to number two on the English charts. It can be found on current Fleetwood Mac compilation releases.

Then Play On’s first single was “Rattlesnake Shake”, Green’s ode of sexual frustration, backed by “Coming Your Way.” The album also featured the popular concert staple, “Oh Well,” which inspired Jimmy Page’s “Black Dog” on Led Zeppelin IV a few years later. It was issued as a single and climbed to fifty-five. It offered a glimpse of Green’s growing discontent with the music industry. Other tunes include, “Closing My Eyes” and “Showbiz Blues,” also reflections of Green’s troubled state of mind. 

Success did not set well with the guitar maestro and eventually became a problem the entire band was forced to confront. “Money is not important. We should love one another,” Green told the press.

Then Play On contained two songs dedicated to their most fervent fan, Madge from Darlington. “Fighting For Madge” and “Searching For Madge.” Fleetwood wrote of Madge that she was, “an early fan from Darlington who would turn up in the four corners of the British Isles to hear us play. To this day, I’ve never seen anyone so faithful to a band.”

While the album became the most successful in the band’s catalogue to date, Green’s discomfort making big cash continued to present a problem. The issue was bantered back and forth between Fleetwood and Green several times, but they never came to a satisfactory solution. Fleetwood wanted to grow wealthy and live comfortably for a change. He argued they could do something nice with the money they earned like form an orphanage. Green wanted to keep enough for survival and give the rest to charity. Finally, it came to a point where Green could take no more.

In a radio interview, he recalled when the problem began. “I was touring America. Everyone else went to bed, but I had this vision of a man watching TV. There were pictures of starving people in Biafra on the screen. I remember thinking, ‘We can get TV cameras there, but we can’t get them food.’ I realized I was at a crossroads. I had more money than I needed.” He was also concerned, by some accounts, that his presence on stage was overshadowing what he rightfully deemed the considerable talents of Jeremy Spencer and Danny Kirwin. “The ambition that he once had,” said Mick Fleetwood, “took him to the top of the mountain and then he said, ‘Well, so what?’ and the only sort of alternative he had, basically was to throw himself off the mountain, which is what he did.”

True to his word, Green left the group in May. News of his departure made the front pages of the British tabloids, the musical press and journals across the world. “I want to change my whole life,” he told the press. “Because I don’t want to be all a part of the conditional world as much as possible I’m getting out of it.” Mac had lost their spiritual and musical leader. McVie described the experience as “trauma city.” Word spread falsely that the hottest, most progressive band in Europe was about to break up. Fleetwood and McVie vowed to do all they could to keep the band alive. A European tour, scheduled to begin in June 1970 however, was canceled.