Simon Waronker, 90, the founder of the independent pop music label Liberty Records, died June 7 at his home in Beverly Hills, Calif. No cause of death was announced.

In the 1950s and 1960s, Liberty Records scored major hits with the novelty recordings of Alvin and the Chipmunks, a fictional musical group created by Ross Bagdasarian under the stage name David Seville. "The Chipmunk Song," released in 1958, sold more than 4 million copies in seven weeks and became a No. 1 single in the United States.

Other artists on the label included Julie London ("Cry Me a River"), Martin Denny ("Quiet Village"), Eddie Cochran ("Summertime Blues"), Johnny Burnette ("You're Sixteen"), Gene McDaniels ("Tower of Strength"), Buddy Knox ("Lovey Dovey") and Timi Yuro ("Hurt").

Mr. Waronker, who was born in Los Angeles, trained as a classical violinist in Europe as a teenager in the early 1930s. After returning to Los Angeles, he played violin in a strip theater for a dollar a day and, after working in a club in San Francisco, played in the orchestra for the 1936 movie musical "Anything Goes."

He was a member of the 20th Century Fox orchestra for three years before serving as orchestra contractor at the studio from 1939 to 1955, when he founded Liberty Records.

Using the furniture in his house as collateral, Mr. Waronker borrowed $2,000 from a Los Angeles bank and used half of the loan to arrange to have Capitol Records' pressing plant manufacture his initial releases. In the beginning, he worked at 20th Century Fox from 9 a.m. to 6 p.m. and then ran Liberty from a rented desk in a Beverly Hills office until 5:30 a.m.

On the lookout for new talent to sign to his label, Mr. Waronker discovered sultry singer Julie London at the 881 Club on La Cienega Boulevard, and within a year of Liberty Records' launch, London's "Cry Me a River" had gone gold.

In 1963, Mr. Waronker sold Liberty Records to Avnet, an electronics corporation, for $12 million.

Survivors include a son and daughter; a sister; eight grandchildren; and two great-grandchildren.