Frank Pellegrino Sr., a sometime actor and the unflappable gatekeeper of Rao’s, his family’s clannish, celebrity-studded and prohibitively exclusive restaurant in East Harlem, died on Tuesday in Manhattan. He was 72.

The cause was lung cancer, his son, Frank Jr., said.

Mr. Pellegrino was a struggling singer playing nightclubs and cruise ships in 1972 when his aunt, whose husband’s father had founded Rao’s, on East 114th Street, in 1896, enlisted him to help out because business was booming.

“I came for two weeks and stayed 44 years,” he told Vanity Fair last year.

Mr. Pellegrino became a co-owner and the man to call for a reservation for one of the restaurant’s coveted four tables and six booths — an exercise in crushed hopes for most would-be patrons; Rao’s says it is booked for the rest of 2017.

Mr. Pellegrino came to be called Frankie No for his firm, egalitarian protocol of turning away the disappointed, regardless of rank.