Even though he accompanied any number of legends during the late 1950s and '60s, Steve Kuhn doesn't have the name recognition of other jazz artists who came of age during that period. But few pianists have maintained as high a standard as he has in the mainstream trio setting.Live at Birdland, which occasions the reunion of one of his best threesomes--the bassist is Ron Carter, the drummer Al Foster, both Miles Davis alumni--is one of his most consistently engaging albums.  A keen intelligence and lively wit is at work on this tuneful terrain, which ranges from the shifting tempos and tones of "Jitterbug Waltz" to the luminous reflection of Carter's "Little Waltz" (which the bassist graces with a lovely solo) to the lovely intersection between Billy Strayhorn's "Passion Flower" and a Debussy waltz, "La Plus Que Lente." There's a romping aspect to the set as well: In his late 60s, Kuhn has lost nothing in speed or agility, rendering Kenny Dorham's "Lotus Blossom" with light-fingered brilliance. If another pianist hadn't stolen the "State of the Art" tag, he certainly could hang out that shingle on this album, one of the most enjoyable in this vein in quite some time.--Lloyd Sachs