Any long-lived band, if it is to remain vital, must evolve from its original purpose, but the on-again, off-again jazz quartet Sphere has moved further than most owing to the narrowness of its initial focus. Sphere was formed in 1979 by two longtime members of Thelonious Monk’s group, the wonderfully idiosyncratic saxophonist Charlie Rouse and drummer Ben Riley, plus two stellar players a generation younger, pianist Kenny Barron and bassist Buster Williams. In taking Monk’s middle name as their own, they signaled their intent to concentrate on the unique compositions that had led to his canonization (Monk was still alive at the time but had played in public only twice since ’73). Sphere stuck to that agenda on their early albums, but their concert repertoire included compatible material by other artists almost from the beginning. Lately the balance has shifted in the opposite direction: their 1998 release Sphere (Cyclops) included a couple of Monk tunes, but the bulk of the tracks were jazz classics by other composers and originals, mostly by Barron. That album was Sphere’s first in a decade: the band had drifted after Rouse’s death in ’88, then reconvened with the addition of alto man Gary Bartz, who plays with a hard-edged passion that has little in common with the slippery insinuations of his predecessor’s best work. Once a sideman to Miles Davis and McCoy Tyner, Bartz had gone through a dry period in the mid-to-late 80s and early 90s, but he reemerged with a smoldering fire, banked by maturity and experience, that’s placed him among the great altoists on the contemporary scene. Williams and Barron provide the band’s dynamic, churning core, and Riley, who represents the band’s last direct link to Monk, remains a marvelously swinging and sensitive drummer; the marriage of taste and drive in his playing is reminiscent of that of the Modern Jazz Quartet’s Connie Kay. No matter whose tunes they play, they’re a great and significant quartet. Tuesday through Thursday, November 11 through 13, 8 and 10 PM, Friday and Saturday, November 14 and 15, 9 and 11 PM, and Sunday, November 16, 4, 8, and 10 PM, Jazz Showcase, 59 W. Grand; 312-670-2473.

Art accompanying story in printed newspaper (not available in this archive): photo/Phoebe Ferguson.