His family announced the death but did not provide a cause.

For more than 25 years, Alpert and Mr. Moss presided over one of the industry’s most successful independent labels, releasing such blockbuster albums as Albert’s “Whipped Cream & Other Delights” (1965), Carole King’s “Tapestry” (1971) and Peter Frampton’s “Frampton Comes Alive!” (1976).

A&M was home to the Carpenters and Cat Stevens, Janet Jackson and Soundgarden, Joe Cocker and Suzanne Vega, the Go-Gos and Sheryl Crow. Among the label’s singles: Alpert’s “A Taste of Honey,” the Captain and Tennille’s “Love Will Keep Us Together,” Frampton’s “Show Me the Way” and “Every Breath You Take” by the Police.

Mr. Moss was inducted with Alpert into the Rock and Roll Hall of Fame in 2006.

Jerome Sheldon Moss was born in Brooklyn on May 8, 1935, and graduated from Brooklyn College in 1957. After a six-month Army stint, he found work as a promoter for Coed Records and eventually moved to Los Angeles, where he met and befriended Alpert, a trumpeter, songwriter and entrepreneur.

With an investment of $100 each, they formed Carnival Records and had a local hit with “Tell It to the Birds,” an Alpert ballad released under the name of his son, Dore Alpert. After learning that another company was called Carnival, Alpert and Mr. Moss used the initials of their last names and renamed their business A&M, working out an office in Herb Alpert’s garage and designing the distinctive logo with the trumpet across the bottom.

“We had a desk, piano, piano stool, a couch, coffee table and two phone lines. And that for the two of us worked out very well, because we could go over the songs on the piano and make phone calls to the distributors,” Mr. Moss later told Billboard. “We also had an answering service at the time. I’d do all my own billing.”

For several years they specialized in “easy listening” acts such as Alpert and the Tijuana Brass, Brazilian artist Sérgio Mendes and the folk-rock trio the Sandpipers. After attending the Monterey Pop Festival in 1967, rock’s first major festival, Mr. Moss began adding rock performers, including Cocker, Procol Harum and Free.

One of their biggest triumphs was “Frampton Comes Alive!” a live double album that sold more than 6 million copies in its first year and transformed Frampton from mid-level performer to superstar.

“Peter was a huge live star in markets like Detroit and San Francisco, so we made a suggestion that he make a live record,” Mr. Moss told Rolling Stone in 2002. “What he was doing onstage wasn’t like the records — it was outrageously better. I remember being at the mix of ‘Frampton Comes Alive!’ at Electric Lady Studios, and I was so blown away I asked to make it a double album.”

A&M continued to expand their catalogue through the 1970s and ’80s, taking on the Police, Squeeze, Joe Jackson and other British New Wave artists, R&B musicians Janet Jackson and Barry White, and country rockers 38 Special and the Ozark Mountain Daredevils.

By the late ’80s, Alpert and Mr. Moss were struggling to keep up with ever-higher recording contracts and sold A&M to PolyGram for an estimated $500 million. They remained at the label but clashed with Polygram’s management and left in 1993; one of their last signings was a singer-musician from Kennett, Mo: Sheryl Crow. (Alpert and Mr. Moss later sued PolyGram for violating their contract’s integrity clause and reached a $200 million settlement.)

For a few years, Alpert and Mr. Moss ran Almo Records, where performers included Garbage, Imogen Heap and Gillian Welch.

“We wanted people to be happy,” Mr. Moss told the New York Times in 2010. “You can’t force people to do a certain kind of music. They make their best music when they are doing what they want to do, not what we want them to do.”

A complete list of survivors was not immediately available.

Mr. Moss was a savvy investor in racehorses. Giacomo, named for the son of A&M artist Sting, won the Kentucky Derby in 2005. Zenyatta, in honor of the Police album “Zenyatta Mondatta,” was runner-up for Horse of the Year in 2008 and 2009, and won the following year. A hit single by Sting gave Mr. Moss the name for another profitable horse, Set Them Free.