Pianist Eddie Palmieri belongs to that select class of musicians for whom change and development are the holiest of virtues. Over the past four decades he's repeatedly revamped his sound and approach, each time forging a style whose influence continues to ripple through jazz and especially Afro-Caribbean music. Dizzy Gillespie had used Latin rhythms as a catalyzing detail in the late 40s, but Palmieri integrated jazz more fully into Cuban styles in the mid-60s, stretching three-minute dance tunes into eight- and nine-minute jams. His highly percussive playing mixed dissonance with the jagged rhythms of Monk and the harmonic complexity of McCoy Tyner and Bill Evans. And in the 70s Palmieri went on to pioneer Latin funk with Harlem River Drive. But his greatest legacy remains the sound he created in the early 60s with his band La Perfecta. Palmieri hijacked the classic violin- and flute-driven sound of Cuba's elegant charanga music, replacing strings with trombones to create what's sometimes called "trombanga." Palmieri and trombonist-arranger Barry Rogers prefigured salsa's ongoing obsession with that brass instrument, using a two-'bone front line to produce a joyfully aggressive sound and give the music plush, richly modulated depth. In the fall of 2001 Palmieri asked a young trombonist named Doug Beavers (a student of longtime Palmieri associate Conrad Herwig) to transcribe the early recordings of La Perfecta, whose arrangements had been lost years before. His work inspired the pianist, whose work had been erratic for the preceding 15 years, and Palmieri put the music on tape: last year's La Perfecta II (Concord) mixes new tunes with old, and its muscular vitality overpowers any whiff of nostalgia. "Shekere Agent Man," a new composition cowritten by the pianist and trumpeter Brian Lynch, wends through several discrete parts, including a superb jazzy intro with voicings that suggest an old Ray Charles record, while "Tirandote flores II" tweaks the 60s original, arranging Rogers's old solo for three trombonists. Palmieri's razor-sharp playing cuts through the dense sound, and his nonchalant percussive dexterity allows him to perform a veritable symphony of polyrhythmic accents. In these rare small-club appearances he leads an excellent ten-piece group featuring Lynch, trombonists Beavers and Chris Washburne, three percussionists, and a singer. Thursday, March 20, 8 PM, and Friday, March 21, 10:30 PM, HotHouse, 31 E. Balbo; 312-362-9707.