The title is not superficial. Indeed in light of other works (Contours, Colors, Hints On Light And Shadow), it captures something that is central in the artist's oeuvre – shifting hues and shapes, as if the music was a canvas with an array of brush and broad strokes. As he showed on the gorgeous ‘Beatrice’, Rivers can write the most lyrical of themes but he is also a master of mercurial, dot-dash arrangements where short, sharp phrases scurry and stutter, at times emphatically so, but still generate momentum. Sometimes, this is done by all of the members of the band attacking a triplet in different ways, with a personal feel for the ‘one’, and sometimes by the clever juxtaposition of the dry density of the lower register and the springloaded zest of the upper. Hence the wide dynamic range offered by the two poles of George Lewis' trombone, startling in its sensual expanse, and Thurman Baker's marimba, with its discreet, woody understatement.

Dave Holland's bass, alternately brawny and balletic, pivots effectively in the middle. Yet for all the dislocated nature of much of the material, Rivers can also supply a groove of the kind of nonchalant, unhurried funk of which Rahsaan Roland Kirk was a master. Inevitably, the beat does not stay steady forever but it is precisely the unforeseen, playful twists and tangents of the compositions that make Rivers' such a compelling writer. If and when some bright spark gets round to anthologising the work of this very important artist then a track from this set that has aged so handsomely will be an indisputable must.