Mark Isaacs's prowess as a composer and classical pianist lends a subtly pronounced discipline to the jazz trios and quintets he's been leading since the early '90s. You can hear it best in his Resurgence, for whom Isaacs writes complex and inventive long, linear melodies the quintet executes with a fullness of sound and natural accessibility a chamber ensemble might envy. There's still plenty of swing in his bluesier tunes, of course; but the classical materials at Isaacs's disposal—from moody rubato meditations to airy allegros—add another dimension altogether to his music.