Here we have a summit meeting late in the careers of the pioneering titans of Afro-Cuban jazz: Dizzy Gillespie fronting the Machito orchestra on trumpet, with Mario Bauza as music director, alto saxophonist/clarinetist, and organizing force, and Chico O'Farrill contributing the compositions and arrangements.

This could have been just a nostalgic retro gathering 25 years after the fact, but instead, these guys put forth an ambitious effort to push the boundaries of the idiom.

The centerpiece is a 15-minute trumpet concerto for Gillespie called "Oro, Incienso y Mirra," where O'Farrill melts dissonant clusters, electric piano comping, and synthesizer decorations together with hot Afro-Cuban rhythms into a coherent, multi-sectioned tour de force.

Gillespie, who had apparently never been in the same room with synthesizers before, is magnificent as he peels off one patented bebop run after another over Machito's band and in the gaps between.

There is also an equally sophisticated suite of O'Farrill pieces grouped under the title "Three Afro-Cuban Jazz Moods," which mixes rock elements into the rhythms.

Parts of "Pensativo" sound as if O'Farrill had been carefully listening to Santana, the teacher learning from the student, as it were.

It adds up to a paltry 32 minutes of music, yet one can forgive the short length, this being all there is of a historic recording session.