Francis Ford Coppola may have created the “Godfather” films, but these days, the real godfather of the Coppola clan is his uncle Anton Coppola.

“I don’t know if I like the Mafioso connotations of that,” said Mr. Coppola, who is 99 and still composing, conducting and devoting his life to opera. He is also uncle to the actress Talia Shire, and great-uncle to the actors Nicolas Cage and Jason and Robert Schwartzman, and the filmmakers Sofia and Roman Coppola.

Creatively, the maestro is every bit as active as his younger relatives. Besides holding opera rehearsals and master classes, he spends his days composing and arranging in longhand, in the Central Park West apartment he has shared since 1956 with his wife, Almerinda.

Mr. Coppola, a lifelong New Yorker, works at a card table with folding legs by a window overlooking Central Park and Tavern on the Green. He writes out his ideas on long pages, his baby grand piano next to him.