A Dizzy Celebration : Salute: Although jazz giant John Birks (Dizzy) Gillespie, 75, is told by his doctor to bypass a birthday bash on a cruise ship, musicians are giving a stirring tribute to his 55-year career.

ABOARD THE M.V. ZENITH —  Fifty world-class jazz musicians and hundreds of fans are assembled aboard this ship to celebrate the 75th birthday Wednesday of John Birks (Dizzy) Gillespie.

Unfortunately, the guest of honor, who was scheduled to be aboard the cruise, couldn’t make it. Gillespie’s doctor told him that the emotional and physical strain of a weeklong tribute could cause a relapse. The jazz giant has been recuperating from major intestinal surgery last spring.

Informed by producer Charles Fishman hours after the ship sailed Saturday from Fort Lauderdale, Fla., passengers seemed to take the news in stride. Even without Gillespie--a trumpeter who has been big brother, surrogate father or inspiration to the musicians aboard--the cruise promised to be a stirring celebration of the artist’s 55-year career.

“When Dizzy played in Cab’s band, some people wrote him off as a cocky young kid,” recalled Milt Hinton, the bassist who was Gillespie’s colleague in the Cab Calloway orchestra in 1940. “Well, within five years he and Charlie Parker had turned the whole jazz world upside down--new melodic ideas, different harmonies, radical rhythmic concepts. People made fun of be-bop and called it a bunch of wrong notes . . . but eventually everyone caught up.”

“I got my first break with Dizzy, recording with him in Detroit when I was just 19, and gigging with him in a group that included John Coltrane,” said guitarist Kenny Burrell. “He was one of the warmest, most helpful people I ever met, and I would have gone on the road with him, but my mother insisted I finish college. Just that brief time in his company was a life-enriching experience.”

During the first evening of music Saturday--performed at four lounges and bars around the ship--a Gillespie aura pervaded every set. Everyone seemed eager to play one of Gillespie’s compositions--”Night in Tunisia,” “Groovin’ High”--or to reflect on his influence or reminisce about the first time they heard him.

“We met in Philadelphia,” said the 65-year-old trumpeter Red Rodney. “He jammed with me, then sent me train fare to come to New York. At the Three Deuces on 52nd Street he introduced me to Charlie Parker, who took me uptown and introduced me to Miles Davis. A few years later, I followed Dizzy and Miles into Parker’s quintet. He’s been more than a mentor to me--he’s a true mensch .”

Typical of the degree to which jazz has brought the generations together was a collaboration between the quintet of Roy Hargrove, a brilliant 23-year-old trumpeter, and Doc Cheatham, the trumpet veteran who just turned 87.

Another strong undercurrent has been Gillespie’s successful fusion of Latin music with jazz. Sunday evening one of the heartiest ovations was accorded saxophonist Paquito d’Rivera, who in 1980--three years after meeting Gillespie in Havana--became the first big-name jazz defector from Cuba to the United States. For the last five years, he has been a member of Gillespie’s multicultural United Nation Band, which will perform here later in the week.

“If it hadn’t been for Dizzy, I wouldn’t be here,” said Arturo Sandoval, who eventually left Cuba too--in a Havana band called Irakere. “Of course we all knew him from radio and records, but his graciousness and enthusiasm truly inspired us.”

The polyrhythmic character of jazz in the post-Gillespie age was reflected in two striking performances Saturday and Sunday by Randy Weston, the 6-foot-6 piano colossus who has spent much of his adult life in Africa. Playing the Sonny Rollins composition “St. Thomas,” he was backed by the energy-packed conga drumming of Patato Valdes, and by the bass of Al McKibbon, who was a member of Gillespie’s 1948 big band--the first jazz orchestra to bring modern jazz to Europe.

On his birthday Wednesday, a taped message from Gillespie will be played for the guests. Meanwhile, autographs are being collected for a giant postcard to be sent to the absent guest of honor. In the past few years just about every imaginable tribute has come his way. Now comes the climactic salute--perhaps the greatest of all, because it comes from the musicians whose lives in some way were intertwined with his.