Mac Rebennack, the pianist, singer, songwriter and producer better known as Dr. John, who embodied the New Orleans sound for generations of music fans, died on Thursday. He was 77.

A family statement released by his publicist said the cause was a heart attack. The statement did not say where he died. He had been living in recent years on the north shore of Lake Pontchartrain, La.

Mr. Rebennack belonged to the pantheon of New Orleans keyboard wizards that includes Professor Longhair, James Booker, Huey (Piano) Smith and Fats Domino. What distinguished him from his peers was the showmanship of his public persona.

Onstage as Dr. John, he adorned himself with snakeskin, beads and colorful feathers, and his shows blended Mardi Gras bonhomie with voodoo mystery.