Andrew Hill was a great and even ground-breaking composer and pianist, yet the relatively circumscribed scale of his innovations might have originally caused him to get lost in the shuffle of the '60s free jazz revolution. While many of his contemporaries were totally jettisoning the rhythmic and harmonic techniques of bop and hard bop, Hill worked to extend their possibilities; his was a revolution from within. Much of the most compelling '60s jazz was nearly aleatoric; Hill, on the other hand, exhibited a determined command of his materials, however abstract they might sometimes be.