The beloved composer and performer succumbed at approximately 1:30 on Sunday afternoon at Memorial Sloan-Kettering Cancer Center.

Irish Rep regulars will perhaps remember with particular delight the rich contribution made to the group's unquenchable hit show, "The Irish . . . and How They Got That Way," for which he selected and arranged music, played an on-stage piano and contributed pitch-perfect impressions of James Cagney and John Fitzgerald Kennedy, among others. Other appearances with the group included Dylan Thomas's "A Child's Christmas in Wales."

Benjamin Rush Magee, born on Aug. 6, 1955, and familiarly known as "Rusty" because of his strawberry-blond hair, was the second eldest of four sons of Bettie Morris Magee, a former prison psychologist and court administrator, and Kenneth Raymond Magee, a neurologist who died in 1982.

The Benjamin Rush portion of Rusty Magee's name was a recognition of the fact that he was a direct descendant of Benjamin Rush, a physician who was a signer of the Declaration of Independence.

Magee is survived by his wife of 20 years, Alison Fraser, a Broadway singer and actress, and the couple's son, Nathaniel, in addition to his mother and two of his brothers, Kenneth and James. A third brother, Robert, died in Los Angeles almost a year ago.

A native of Ann Arbor, Mich., Magee's musical gifts became evident while he was still a small child. By the time he was 6, he could play the piano by ear, and when he was 10, his maternal grandfather gave him a Steinway Grand, which, symbolically at least, seemed to point the way to the path his professional and personal life would follow.

When he was in the fifth grade, Magee played the lead in a school production of the Broadway classic "Oliver," an experience that served to whet his undying interest in the theatrical end of the musical spectrum.

Magee spent two pre-prep school years at Eaglebrook, in Deerfield, Mass., and then attended Phillips Exeter Academy, graduating in 1973.

After spending a year in Nimes, France, he enrolled at Brown University in Providence, R.I., becoming a member of the graduating class of 1978.

Magee then earned a masters degree from the Yale School of Drama, and even before he completed his classwork in New Haven, he was hired by the Yale authorities to contribute to the institution's musical endeavors.

Once he graduated and arrived in New York, Magee began to work with a Yale classmate, comedian Lewis Black, in shaping the performance schedule for the Downstairs Cabaret of Steve Olson's Westbank Restaurant on West 42nd Street. His association with Westbank lasted very nearly a dozen years.

In addition to his work at Westbank and his ongoing relationship with the Irish Repertory Theatre, Magee had a long and extremely productive participation with the Moonwork Theater Company based at the Cornelia Connelly Theatre on Manhattan's East Fourth Street.

"Mason Pettit, one of our founding members saw Rusty performing, and approached him about working with us," recalled Gregory Wolfe, Moonwork's artistic director.

Moonwork does a series of cabaret benefit evenings aimed at helping sponsor the group's annual productions, which are usually musicals based on the works of William Shakespeare.

Wolfe said: "When we did our version of 'A Midsummer Night's Dream,' he played Peter Quince, one of the play's Rude Mechanicals, and composed the music for the 'dumb show' the comics do toward the end of the story."

Moonwork's 2002 project, the last in which Magee was able to participate fully, was "What You Will." "That's the subtitle Shakespeare gave 'Twelfth Night,' " said Wolfe. "Rusty played the comic Feste, whom he envisioned as a kind of Grade C lounge pianist. With that role, he was really able to put his gifts for parody to work."

Wolfe also remembered, with a kind of awe, Magee's ability to improvise on the spot and also bring his audiences along with him in virtually any direction he chose.

"He could sing from the newspaper headlines, making songs out of them at a moment's notice. He was that inventive," Wolfe said. "He could get the audience to sing along with him without the slightest sense of embarrassment."

Magee's amazing ability to reach and hold an audience was put to work last year when the Irish Rep held its annual benefit on a boat going up and down the Hudson River. He was handling the group's prolonged raffle when the boat edged into place at the dock. Despite the fact that the cruise was over, nobody made the slightest move toward departing until Magee had told the last of his jokes and given out the last of his prizes.

As recently as November of last year, Magee was still doing stand-up comedy routines at Moonwork and elsewhere. In mid-December, he was still composing.

In the summer of 2002, Keith Lockhart, director of the Boston Pops, approached Magee about composing the music for an orchestral adaptation of "Arthur the Aardvark." Magee accepted the commission, but then became so ill that he had to withdraw.

In the spring of 2001, Magee had begun experiencing severe dizzy spells, and his doctors suggested a series of tests, including an MRI. Toward the end of the year, cancer was diagnosed and Magee underwent the first of what would become a lengthy and grueling series of operations and treatments.

Among the prizes and tributes Rusty Magee received is one he valued especially highly. It is the Coming-Up-Taller Humanitarian Award, given by the 52nd Street Project, a group founded by actor and director Willie Reale and dedicated to improving the lives of Hell's Kitchen youth through theater.

The details of a planned public memorial will be released as soon as they are finalized.