The year was 1964 and the band was called the Miles Davis Quintet. In a matter of just four fast and furious years, the group defined the essence of "modern jazz," securing a reputation as the most influential group in jazz history and heralding the emergence of saxophonist Wayne Shorter as the most fiercely innovative and creative composer/instrumentalist of the post be-bop era.

The influence of Miles'' music and his groundbreaking quintet will figure prominently at the MJF Sunday evening when Wayne Shorter takes center stage to debut a new composition commissioned by the festival. The work was first suggested to Shorter by Miles back in 1964, but was only recently rediscovered by Shorter--by accident.

"Miles was always thinking of odd combinations," says Shorter. "Miles gave me the music and said ''Do something with this,'' but I only just found it recently in my piano seat."

According to Shorter, the composition, titled "Vendiendo Alegria," which translates as "Selling Happiness," is based on an old Spanish song recorded in Madrid in the ''40s that caught Miles'' attention during a period when much of his own material reflected a fascination with Spanish-themed music.

Shorter, playing tenor and soprano sax, will perform "Vendiendo Alegria" with a 28-piece brass and woodwind ensemble and a stellar lineup of musicians that includes pianist Danilo Perez, bassist John Patittucci, percussionist Alejandro Acuna and drummer Brian Blades.

In addition to his commissioned piece, Shorter, who just celebrated his 67th birthday last month, will perform two classics that capture the essence of his best work from the ''60s: "Orbits," the opening cut from the Quintet''s second album Miles Smiles, and "Angola," one of Shorter''s more enduring tunes from his series of recordings for Blue Note.

"Vendiendo Alegria" is the seventh composition commissioned by the MJF since Tim Jackson took over at the helm; and as far as Jackson is concerned, Shorter''s appearance at the festival this weekend is both a significant artistic coup and a tribute to Shorter''s tremendous importance and influence on contemporary jazz.

"You''d have to put Wayne in the highest echelons as a jazz innovator," Jackson says. "When you look at the concept of the total musician, that''s Wayne. He''s a marvelous individualistic sax player, a unique innovative writer and a marvelous band leader. He''s one of the great jazz composers recognized across the board from his work with Art Blakey to the Miles Davis Quintet to Weather Report."

Shorter has appeared three times at the MJF. The first time with the original Miles Davis Quintet in ''64; a second time in 1969 with a revamped quintet that included Chick Corea on piano, Dave Holland on bass and Jack DeJohnette on drums; and the last time in 1992 in a "Tribute to Miles Davis."

Although Shorter has taken his share of critical hits over the years for presumably abandoning "traditional, serious" jazz in favor of fusion and pop, he remains indifferent to such criticism and contends that jazz, by definition, is about change and evolution.

"I''m coming from the premise that the word ''jazz'' means no category--that is my definition," says Shorter. In recent years, he has composed numerous commissioned pieces for orchestras throughout the U.S., recorded two albums for Verve Records (a solo album entitled High Life as well as a highly acclaimed duet recording with pianist Herbie Hancock), been active in music education through the Thelonious Monk Institute, and performed internationally with student musicians.

"It is the creative process itself that is the prime mover," he continues. "You have to go to extremes, you''ve got to be creative and willing to take chances to the point that perfection is not desired, because that ends everything. I guess you might say I''m aiming for music without boundaries."