Robert Merrill, 87, the baritone who gave his booming voice to major roles at the Metropolitan Opera for more than 30 seasons while winning nationwide popularity on radio and television and at baseball games, died Oct. 23.

He was watching the World Series on television at his home in New Rochelle, N.Y., when, according to his son, David, "his heart just stopped."

Mr. Merrill was one of the foremost and most enduring of the generation of home-grown performers who took on the great roles of French and Italian opera at the Met in New York after World War II.

Rich, warm and powerful, his voice offered vivid life to more than 20 roles during more than 500 performances in the nation's premier operatic venue.

In addition, he won a wide following on radio and television, as a popular entertainer with a repertoire that extended to operetta, Broadway and Tin Pan Alley. He was a frequent guest on talk shows, blending high and popular culture.

He sang the national anthem on Opening Day at Yankee Stadium in 1969, and he continued the tradition for years, in addition to appearing there at the playoffs and World Series.

Although students of opera occasionally claimed to see shortcomings in his dramatic interpretations, he was widely admired for the resonance and ring of his notes and the size of his voice.

"If you think you've hit a false note," he once was quoted as saying, "sing loud. When in doubt, sing loud."

In 1993, during President Bill Clinton's first year in office, White House ceremonies were held to honor 18 of the nation's leaders in the arts and humanities.

In a memorable impromptu moment, Leontyne Price rose after dinner to sing "Stardust," and Merrill followed with "I'll be Loving You (Always)."

"It was awesome, wasn't it?" Clinton said.

Merrill was born June 4, 1917, and was originally named Moishe Miller. Although he loved baseball and thought of trying to make a career of it, his mother guided him into voice training. "She recognized [his gift] and steered him in the right direction," his son said.

After appearances on radio and on the stage of Radio City Music Hall, he won the Met's "Audition of the Air" in 1945. That December, he made his debut as Germont in Verdi's "La Traviata."

The 1960s were described as the peak of his operatic career. But it extended into the 1970s, giving him a longevity that few matched. He was said to be the first American singer to perform 500 times at the Met.

He was also known for his on-air performances in such shows as "The Bell Telephone Hour" and "The Voice of Firestone." These, in addition to recordings, variety shows and the Met's radio broadcasts, brought his voice into living rooms far beyond Manhattan. He played Tevye on stage in "Fiddler on the Roof."

Among the operatic roles for which he was known were Amonasro in "Aida," Renato in "Un Ballo in Maschera" and Escamillo in "Carmen." He sang Valentine in "Faust" and Marcello in "La Boheme."

He was renowned as Figaro in "The Barber of Seville," his favorite opera. He opened the Met's 1954 season as Figaro.

A brief marriage to soprano Roberta Peters ended in divorce.

Survivors include his wife, Marion, their son and their daughter, Lizanne.

Robert Merrill, shown in 1978, sang at the Met more than 500 times.