Bobby Parker, a soul-blues singer and guitarist whose recordings from the late 1950s and 1960s — notably the propulsive groove of “Watch Your Step” — influenced performers as varied as John Lennon, Carlos Santana and the band Led Zeppelin, died Oct. 31 at an emergency care facility in Bowie, Md. He was 76 and lived in Temple Hills, Md.

The cause was a heart attack, said a friend, Omar Ashaka.

The Washington-based bluesman cut a swaggering figure on stage with his preacher-like exhortations to “say yeah, children,” his shiny suits and his lacquered, James Brown-style hairdo. His tenor voice both caressed and screamed the blues over his powerful, stinging — and sometimes over-amped — lead guitar. And he loved to walk the bar or walk through the crowd as he worked the strings.

Reviewing a 1993 nightclub performance, music critic Peter Watrous of the New York Times wrote that Mr. Parker would “play beautifully formed blues ideas, then throw in be-bop lines worthy of George Benson. . . . Though slightly ruffled by distortion, his notes, pearly and fat, skip along to their own undulating rhythms. And his singing, a high tenor moan, conveys more musical authority than emotional weight. . . . He was showing off his virtuosity there, as well.”

A veteran of the “chitlin’ circuit” of black theaters, Mr. Parker wrote two much-covered hit recordings on the rhythm-and-blues charts, “Blues Get Off My Shoulder” (1958), a somber blues ballad enlivened by his trenchant guitar work, and “Watch Your Step” (1961).

Bobby Parker during a rehearsal in 1983. (Craig Herndon/The Washington Post)

Watch Your Step,” recorded at Edgewood Studios at 16th and K Streets for V-Tone records, was a hit in the United States and England. The song’s insistent riff, which Mr. Parker said evolved from the Afro-Cuban jazz composition “Manteca,” caught on with the mod subculture in London.

Jefferson Airplane, Santana and the Spencer Davis Group (with singer Steve Winwood) all covered the song. Its guitar motif was reprised in Led Zeppelin’s “Moby Dick” and the 1962 instrumental “The Black Widow” by fellow Washington guitarist Link Wray.

The influence of “Watch Your Step” extended to John Lennon of The Beatles, who acknowledged in a 1974 radio interview that “Day Tripper” and “I Feel Fine” were attempts to write songs built on variations of the “Watch Your Step” riff. (Mr. Parker’s record had been released in Germany while the Fab Four were paying their dues at Hamburg’s Star-Club.)

However, Mr. Parker reaped few rewards from the song’s success. He sold the copyright to V-Tone records owner Ivan Mogull for a pittance in the early 1970s.

“I didn’t do my homework when it came to [copyright] protections,” he later told The Washington Post. “We just cut songs. And all of them got away from me.”

Mr. Parker’s career was dogged by bad business decisions. During a Led Zeppelin tour that came through the Washington area in the early 1970s, band guitarist Jimmy Page sat in with Mr. Parker at the Bolling Air Force NCO club. The band, then searching for acts for their Swan Song record label, loaned him money for a tape recorder. However, Mr. Parker — perhaps fearful after having sold a major copyright away — never turned in the demo tape.

In the 1990s, Mr. Parker returned to the national limelight with two critically acclaimed CDs for the New Orleans label Black Top records, “Bent Out Of Shape” (1993) and “Shine Me Up” (1995), and later toured with Carlos Santana. A concert appearance with Santana at Switzerland’s 2004 Montreux Jazz Festival was later released on DVD as “Carlos Santana Presents Blues At Montreux.”

“Bobby Parker is a musician of the same caliber as Albert King and Albert Collins,” Santana told Guitar Player magazine in 1996. “He’s one of the few remaining guitarists on this planet who can pierce your heart and soothe your soul.”

Robert Lee Parker was born Aug. 31, 1937, in Lafayette, La., and raised in Los Angeles. His mother sang in a gospel group, and his father was a distributor of jukebox records. A complete list of survivors could not be confirmed.

In his teens, Mr. Parker left home to tour as guitarist for the doo-wop group Otis Williams and the Charms.

He played guitar behind Bo Diddley on “The Ed Sullivan Show” in 1955. Later, he toured and recorded as vocalist and guitarist in the band of Detroit saxophonist Paul “Hucklebuck” Williams, where he replaced his idol, singer Little Willie John.

The Williams unit served as a backup band at the Apollo Theater in Harlem and on several touring rock-and-roll package shows where Mr. Parker backed luminaries such as Sam Cooke and Fats Domino, often doubling on lead guitar or bass guitar as needed.

Mr. Parker settled in Washington, where he led his own band throughout the early 1960s. His regular local engagements included the Tip Top Club in Bladensburg and the Flamingo Club in the District.

In 1969, Mike Vernon, producer of the British blues band Fleetwood Mac, brought Mr. Parker to England at the height of the psychedelic era. The tour troubled Mr. Parker.

“They wanted me to act like [Jimi] Hendrix, and I was a traditional bluesman,” he later told The Post. “It was a disappointment that everybody was channeled that way and not perceptive to other things.

“I had two nice little guitars and they wanted me to break them up” like Hendrix, he recalled. “I said, ‘Man, I’m not breaking up my guitars.’ ”