Bob Welch, whose mysterious and mystical Fleetwood Mac songs Bermuda Triangle, The Ghost and Hypnotized helped pave the way for his replacement, Stevie Nicks, and the group’s greatest success after his departure, has died at age 65 of a self-inflicted gunshot wound.

Welch’s body was found by his wife in their Nashville home Thursday afternoon, the Associated Press reported. He left a suicide note, and had been struggling with unspecified health issues.

His death seemed sadly foreshadowed by a lifetime of small victories and bitter disappointments. The singer/guitarist with the mellow voice and sophisticated air led Fleetwood Mac from 1971 until 1974 and, with Christine McVie, sang lead on most of the band’s material during that period.

His songs on albums like Bare Trees, Penguin and Mystery to Me, especially Sentimental Lady and the FM-radio classic, Hypnotized, helped establish Fleetwood Mac in the United States. Prior to joining the band as a replacement for iconic guitarist Peter Green, the group was known as a premier blues act in England in the late 1960s.

By 1969, Fleetwood Mac was outselling the Beatles and the Rolling Stones abroad with Green’s songs Black Magic Woman (a hit later for Santana), Oh Well and the instrumental Albatross.

But in America Fleetwood Mac was largely unknown and its brand of authentic blues was not in tune with easy-listening pop acts like Elton John, the Carpenters and Carole King.

Welch’s sound — polished, radio-friendly yet moody and bewitching on songs like Sentimental Lady, Future Games and Emerald Eyes allowed the band to sell a steady 250,000 copies per album, good enough to keep the members signed and on the college touring circuit. More importantly, Welch helped Fleetwood Mac develop its distinctive male-female vocal blend that would prove formidable when Nicks and Lindsey Buckingham replaced him on New Year’s Eve 1975, after he quit.

In that respect, Welch joined Peter Best as rock’s unluckiest man. Best, of course, was the Beatles’ original drummer who toiled in obscurity with the pre-Fab Four before Ringo Starr’s arrival. Within a year of Welch’s departure, Fleetwood Mac hit No. 1 in America in 1976 with an eponymous album.

From that Fleetwood Mac LP, Nicks’ signature smash Rhiannon, which she always introduced on stage as “a song about a Welsh witch,” was a clear extension of Welch’s fascination with the otherworldly — UFOs, strange disappearances in the Bermuda Triangle off the coast of Key Biscayne and ghosts.

Nicks agreed to join Fleetwood Mac, she said, only after listening to Welch’s albums with the group and finding a common mystical thread that she could hear herself fitting into.

Fleetwood Mac’s next album, Rumours in 1977, went on to become one of the best-selling releases in history. At the same time, Welch had formed Paris, a heavy metal band. It went nowhere.

His fortunes rose, however, when Mick Fleetwood became his manager later that year and Welch enjoyed an initially popular solo career.

His first solo album, French Kiss in late 1977, featured a remake of his 1972 Fleetwood Mac song Sentimental Lady, and it sailed into the Top 10. The more buoyant version was produced by Buckingham and also featured McVie and Fleetwood as guests. Welch also had Top 40 hits with Ebony Eyes, Hot Love, Cold World and the quasi-disco Precious Love through 1979.