Hal Schaefer, Fort Lauderdale jazz pianist, vocal coach and arranger, launched his career with Benny Carter, played with Harry James, Billy Eckstine and Ella Fitzgerald, opened shows for Duke Ellington, and coached Judy Garland.

But he became best known in Hollywood for a brief, dangerous liaison with the sexiest movie star of the 1950s: Marilyn Monroe.

It happened after she split with baseball great Joe DiMaggio, he told The Miami Herald in 2001.

Schaefer had been coaching Monroe, who’d come to him through Jack Cole, the “Gentlemen Prefer Blondes” choreographer.

He never thought of Monroe as a sex goddess, he said, but she was insecure and needy, and he succumbed.

DiMaggio, he said, “was insanely jealous,” and was determined to catch his wife in the act.

On Nov. 5, 1954, as he dined with buddy Frank Sinatra, The Yankee Clipper heard that Marilyn and another man could be found at an apartment in West Hollywood.

The two men, with others, broke down the door of the ostensible love nest, terrifying the woman who lived there, who was not Marilyn Monroe.

The incident, which came to be known as “the wrong door raid,” resulted in a lawsuit filed by Mrs. Florence Kotz Ross against Sinatra, DiMaggio and four others, which was settled for $7,500.

The lovers were down the hall, heard the noise, and fled.

Schaefer, who’d heard all he needed to know about Sinatra’s Mob connections, tried to kill himself by drinking typewriter cleaning fluid.

He survived, married Leah Cahan, divorced, then married the British-born Brenda Goodman, whom he called the great love of his life. After she died in 2000 of cancer, at 64, he released a CD titled A Date To Remember: June 1st, the birth date of both his beloved Brenda and Marilyn.

It includes original compositions called Blues for Marilyn and Blues for Brenda.

Born Harold Herman Schaefer in Queens on July 22, 1925, Schaefer died Dec. 8 at home in Fort Lauderdale. A friend, Charles Bryant, told The New York Times that the cause was congestive heart failure. He was 87.

Schaefer went to work at hotels in the Catskills after graduating from the High School of Music and Art in Manhattan.

He made his way to Hollywood, where he worked as arranger and vocal coach. He coached Monroe through “Diamonds Are a Girl’s Best Friend,” her signature number in Gentlemen Prefer Blondes, as well as her co-star Jane Russell.

He also worked with Mitzi Gaynor and Betty Grable, and wrote film scores.

In a 1982 review, New York Times critic John S. Wilson called Schaefer “a romantic with a rhythmic soul. Mr. Schaefer is very much a mainstream pianist, but he has his own way of looking at the mainstream, enlivening the relatively standard repertory that he played with fresh and entertaining ideas.”

In addition to his wife, Schaefer also outlived a daughter and a sister. He is survived by a brother, Robert Schaefer of California.

A memorial service was held.

Material for this story was taken from a New York Times obituary by Bruce Weber.