Bob Welch, who was a key member of the pop group Fleetwood Mac in the early 1970s before scoring several minor hits as a solo performer, died Thursday at his home in Nashville. He was 65.

According to police, he died of a self-inflicted gunshot wound. He left a suicide note.

Welch was a guitarist, vocalist and songwriter for Fleetwood Mac from 1971 to 1974. The band was formed in England in the late 1960s by guitarist Peter Green; its name derived from those of two members of the group, drummer Mick Fleetwood and bassist John McVie.

After Welch replaced Green in 1971, he had a major part in reshaping Fleetwood Mac’s sound to a sweeter, more pop-oriented approach. He wrote the song “Hypnotized,” which appeared on the group’s 1973 album, “Mystery to Me,” and was a key member of the band through five albums.

“He was a huge part of our history, which sometimes gets forgotten,” Mick Fleetwood told Rolling Stone. “Mostly his legacy would be his songwriting abilities that he brought to Fleetwood Mac, which will survive all of us.”

Welch left the band in 1974, just before singer Stevie Nicks and guitarist Lindsey Buckingham joined the group. The reconstituted band had its breakthrough albums with “Fleetwood Mac” in 1975 and “Rumours” in 1977, both of which reached No. 1 and sold millions of copies.

“A strong argument can be made that without Welch’s contributions, Fleetwood Mac would not have been in the position to make ‘Rumours’ in 1977,” Cleveland Plain Dealer critic Michael Norman wrote in 1998. “Welch pushed the band toward the pop mainstream in albums such as ‘Future Games,’ ‘Bare Trees,’ and ‘Heroes Are Hard to Find.’ ”

After leaving Fleetwood Mac, Welch briefly led another band in England before becoming a solo artist. He scored his biggest hit in 1977 with “Sentimental Lady,” a catchy pop song that he first recorded with Fleetwood Mac.