Vassar Clements, a virtuoso fiddle player who transcended genres and influenced generations of bluegrass musicians, died of lung cancer Aug. 16 at his home outside Nashville. He was 77.

A self-taught musician who mastered the violin (or fiddle, as he usually called it) by age 14, Mr. Clements began his career with Bill Monroe and His Blue Grass Boys in 1949 and worked with country artists through the 1960s. He found his greatest success beginning in 1972 by performing with the Nitty Gritty Dirt Band on the popular album "Will the Circle Be Unbroken." From then on, he made a series of boundary-breaking recordings with mandolinist David Grisman, the Grateful Dead's Jerry Garcia and jazz violinist Stephane Grappelli, among others.

Absorbing almost every conceivable style of music, Mr. Clements invented what he called hillbilly jazz, a blend of country music, jazz and swing that characterized his eclectic style. He was known as the "Isaac Stern of the fiddle" or the "Miles Davis of bluegrass."

It would be hard to find anyone who worked with musicians from more widely varied backgrounds, from Hank Williams Sr. to alt-rocker Dave Matthews. Mr. Clements released 27 albums as a leader and, in a 60-year career, performed on as many as 3,000 recording sessions with other artists, including B.B. King, Paul McCartney, Johnny Cash, the Allman Brothers, Emmylou Harris, members of Miles Davis's groups, Buck Owens and the Boston Pops.

"He was a musical giant," Grisman, one of his frequent collaborators and the producer of his final album, "Living With the Blues" (2004), said yesterday. "He had an incredible sound. He had incredible imagination. He was a fountain of ideas and could execute them amazingly."

Although he was most closely identified with country music and bluegrass, Mr. Clements had a sensitivity for jazz and blues that often came out in his playing. He attributed his broad musical approach to the variety of music he heard as a boy.

"Actually, I heard more swing than country or bluegrass while I was growing up in Florida," he once said. "I've always loved that kind of rhythm."

"He was listening to a lot of jazz and a lot of horn players," bluegrass musician Ricky Skaggs said yesterday in a telephone interview. "He was just real open with his playing and went places musically that other musicians weren't going. He would break out a whole vocabulary of licks that nobody else was doing on the fiddle."

Possessing a craggy, expressive face, Mr. Clements often smoked a pipe while performing and had an unvarnished, down-home way of speaking. Even as renowned musicians flocked to hear him, he was never awed by the company he kept.

In 1995, he told the Orlando Sentinel about someone who came to one of his recording sessions: "He was in the studio with them dark glasses on. . . . I finally asked after he left, who was that sitting down there, because he never done anything, he just set there. They said that was Bob Dylan. Boy, I'd never have known that. I thought he mighta just been asleep or something."

Mr. Clements was born April 25, 1928, in Kinard, Fla., and grew up in Kissimmee, Fla., then a cow town near Orlando. He had no musical training except what he heard on the radio or from jukeboxes in the black section of town. He played the guitar before switching to violin.

"My stepfather went and got one at an old furniture store and put some kind of strings on there," he recalled. "I didn't know how to tune it; I didn't know what the bow was for."

He first tried out for Monroe, the "father of bluegrass," at 14 and was rejected. He was an instant sensation when he joined Monroe in 1949 at age 20.

"His first recording with Bill was 'New Mule Skinner Blues,' " Grisman said. "His solo on that recording is one of the cornerstones of bluegrass fiddle playing."

Mr. Clements worked with Monroe until 1956. He struggled with alcohol in the early 1960s and dropped out of music for several years before moving to Nashville in 1967. In the late 1960s and early 1970s, he resumed touring with Faron Young, John Hartford and banjo superstar Earl Scruggs before his breakthrough appearance on "Will the Circle Be Unbroken." He made his first record under his own name ("Crossing the Catskills") in 1973 and, the same year, performed with Garcia and Grisman on "Old and In the Way," one of the top-selling bluegrass albums ever.

He appeared in Robert Altman's 1975 film "Nashville" and continued to perform at festivals, concerts and bluegrass clubs until February.

Mr. Clements was proficient on viola, cello, string bass, guitar and banjo, but his primary instrument was the violin. He played a 400-year-old French violin given to him by Hartford, with the head of a bearded man carved on the scroll.

His marriage to Jean Clements ended in divorce. His wife of 34 years, Millie Clements, died in 1998.

Survivors include two children from the first marriage and three from the second, and 12 grandchildren.

In an interview last year with the Web site, Mr. Clements reflected on his long career: "When I think of how long I've been playing, I think, 'Golly bum, I'm getting old.' "

Vassar Clements began playing fiddle with Bill Monroe and the Blue Grass Boys at age 20.