A new school of piano, which has its roots in the jazz tradition yet uses folk, ethnic and other sources, is in full bloom. Its improvisation is free and its emotional content is often of a deeply personal nature. John Coates Jr. may well be the dean of the school.

Coates' first set at the One Step Down last night identified him from the outset as a highly individualistic and disciplined artist. He juxtaposed idyllic calm and jarring dissonances, he hammered percussively and he hummed constantly. His extended versions of several standards and three or four of his own compositions aroused powerful emotions.

A piece might begin with some noodling, work up a repetitive two- or three-note motive, add a bit of walking bass, burst into a few bars of barrel-house blues, pour a cascading waterfall down the length of the keyboard and then introduce the melody of the tune at hand, say, "Danny Boy" or Sonny Rollins' "Doxy." Words make Coates' approach seem fragmented and eccentric but his playing was absorbing and deeply satisfying.

Bassist Paul Langosch, a longtime associate of Coates, joined in for the last couple of numbers. The two are to perform again tonight.