Margo J. Sylvia, 55, singer best known for her hit “Happy, Happy Birthday Baby” with the 1950s group the Tune Weavers, died Oct. 25 in San Diego of a heart attack and stroke.

Born April 4,1936, Sylvia started a singing duo with her older brother Gilbert Lopez in the mid ’50s in Boston. Sylvia’s then-husband, John, and cousin Charlotte Davis later joined them to form the Tone Weavers. When a disc jockey emceeing a dance in Boston called them the Tune Weavers by mistake, the group decided to keep that name.

After working with other groups’ hits, Gilbert suggested they record new material. They tried a song Sylvia had written about five years earlier, called “Happy, Happy Birthday Baby.”

The group soon signed with Chess records in Chicago, and the record was released on their Checker label.

In August 1957, “Happy, Happy Birthday Baby” became a gold record, reaching No. 3 on the rhythm & blues chart and No. 5 on the pop chart. After that, the group left Checker records, never to have another hit.

Sylvia subsequently worked as a solo performer around the country. She moved from Boston to San Francisco in 1981 and then to San Diego in 1990.

She was scheduled to sing in four California cities in mid-November on a concert tour with other 1950s singers entitled “The Golden Voices of Rock ‘N’ Roll.”

Survived by a granddaughter, Maena Bell.