Mr. LaFlamme and members of his band, It’s a Beautiful Day, sampled from the mix of folk, rock and psychedelia in San Francisco as they shared gigs and swapped ideas with groups such as the Grateful Dead and Jefferson Airplane. Mr. LaFlamme’s addition of the violin — with driving crescendos and soulful adagio — brought flowing subtleties different than anything guitars or keyboards could match.

“White Bird” emerged as a collaboration with his then-wife and keyboardist, Linda Neska, for the group’s debut album in 1969, “It’s a Beautiful Day” — a name taken from the joyful cry of a passing motorist one sunny afternoon. The song became the group’s signature work and part of the soundtrack of the 1960s from its opening harmony by Mr. LaFlamme and vocalist Pattie Santos:

And then the song’s message as a refrain: “White bird must fly/Or she will die.”

Mr. LaFlamme, who also played guitar, described the song as a struggle between the pull of freedom and the compromises of conformity. “The white bird in a golden cage represents someone trying to break out of the constraints of the affluent middle class,” he later said.

The song’s setting — a dreary day as “leaves blow across the long black road” — was drawn from personal experience. Mr. LaFlamme and his wife were living in a Victorian house in Seattle during a series of performances the winter of 1967-68, working on music in the attic with a Wurlitzer portable piano under a window. “We were looking out from the attic window over the street in front of this old house … It’s describing what I was seeing out the window,” Mr. LaFlamme wrote on his website.

At first, “White Bird” struggled to find an audience. It didn’t rise far the charts and was a difficult fit for AM radio at the time because of its length, more than six minutes, and the novelty of Mr. LaFlamme’s violin solo in the middle. But FM stations, particularly the counterculture formats on college radio, embraced the song and the group as hippie troubadours, including other tracks from the album such as “Wasted Union Blues,” “Girl With No Eyes,” and the instrumental “Bombay Calling.”

“White Bird” gradually was adopted as part of the 1960’s musical canon, and Mr. LaFlamme was credited as an influence on violinists including bluesman Papa John Creach and his work with Jefferson Airplane and Hot Tuna; Robby Steinhardt with the rock group Kansas, and Scarlet Rivera with Bob Dylan on songs such as “Hurricane,” released in 1976.

Over a career spanning more than five decades, Mr. LaFlamme showed no surprise that the violin found a niche alongside rock guitars and thumping bass lines.

“I think that the violin probably more than any other instruments closely mimics the voice and my first love was singing and the voice,” he said in a 1998 interview with music writer John Barthel, “and I think violin an extension, the closest extension of that.”

David LaFlamme was born on May 4, 1941, in New Britain, Conn., and spent much of his boyhood in Salt Lake City. (According to some sources, he was born Gary Posie.) His father worked in a copper mine, and his mother was a homemaker.

He received his first violin at 5 years old as a gift from an aunt and uncle, whose daughter lost interest in the instrument. “So I began fooling around with it on my own and taught myself to play ‘Twinkle, Twinkle Little Star,’” he recalled. His parents were impressed and arranged for a teacher, who introduced him to classical violinists and composition.

Mr. LaFlamme served in the Army in the early 1960s at Fort Ord, near Monterey, Calif., and was discharged after experiencing some hearing loss from test firing weapons. He had spent time in San Francisco while on military leaves and headed back to the city in 1962 with a duffle bag — “mostly just Army clothes” — and a “few bucks in my pocket,” he told the music site Exposé in 2003.

He began jamming on guitar and violin in parks and clubs with musicians shaping the San Francisco sound: Jerry Garcia; Janis Joplin and Country Joe and the Fish. Mr. LaFlamme formed his first band, the Electric Chamber Orkustra, in 1966 and then was part of Dan Hicks & His Hot Licks.

In the summer of 1967 — what became known as the “Summer of Love” — Mr. LaFlamme and his wife put together It’s a Beautiful Day with vocalist Santos, guitarist Hal Wagenet, bassist Mitchell Holman and drummer Val Fuentes.

A major break came in October 1968 when singer and guitarist Stevie Winwood of the band Traffic came down with a throat condition and couldn’t perform in a joint gig with Cream at the Oakland Coliseum. The concert promoter, Bill Graham, contacted It’s a Beautiful Day as a fill-in. A record deal with Columbia soon followed.

The group released its second album, “Marrying Maiden,” in 1970, which included Garcia playing banjo on the song “Hoedown” and pedal steel guitar on “It Comes Right Down to You.”

The band broke up in 1973 after two more albums and tours that included once opening for the Who in Paris. It’s a Beautiful Day was booed and the crowd started chanting “Tommy” for the Who’s 1969 album, Mr. LaFlamme recalled.

“The funny thing was,” he told the Salt Lake Tribune in 1983, “I wanted to hear the Who just as much as they did.”

A legal battle over ownership of the band’s name forced Mr. LaFlamme to build new groups under different banners, including Edge City. He released a solo album in 1976, “White Bird,” with a new version of the title song, which peaked at No. 89 on the Billboard Hot 100.

Over the next two decades, he was part of more than 10 other albums as a solo artist or under It’s a Beautiful Day after wrangles over the name ended.

His first marriage, to Linda Neska, ended in divorce. He married singer Linda Baker in 1980. Complete information on survivors was not immediately available.

The creation of “White Bird” took about two hours, said Mr. LaFlamme’s first wife. She worked on the chords while he crafted the lyrics. They shared duties on the melody.

“The song kept evolving, but that was the birth of ‘White Bird,’” she told the music site Please Kill Me in 2020. “When we finished after two hours, David and I looked at each other, and we knew we had a beautiful song.”