The release of Azure, a duo recording by bassist Gary Peacock and pianist Marilyn Crispell, may have been inevitable, but it sure was a long time coming. Peacock and Crispell have played together on tour for years, but this is their first opportunity to record as a pair. Under Crispell's leadership, they teamed with the late Paul Motian on two of the finest piano trio offerings of the last two decades: Nothing Ever Was, Anyway and Amaryllis. There are three tunes composed by each artist, three duo improvisations, and each has a solo track. Crispell's "Patterns" opens the proceeding on a lively note. A complex, knotty, muscle-flexing duet that is full of quick call-and-response motivic thought and counterpoint, it reveals the duo's considerable dialogic power. On the other end of the spectrum is Peacock's lovely, melodic "The Lea," which extends naturally from both the folk and blues traditions. He opens with his solo; it states its loose theme followed by his improvisation upon it for half the tune's length. When Crispell enters, she underscores the song-like nature of the piece, painting its frame with melancholy, minor-key chord voicings, and brief, luxuriant fills. The set's longest cut, "Waltz After David M," by Crispell, is elliptical and graceful with a gorgeous melody. Peacock's support offers avenues for more expansive -- yet subtle -- thought in the middle's long improvisational section. Though these pieces are quite satisfying, the duo's real poetic is displayed in their improvisations, especially the hypnotic "Blue," with Crispell's Monk-tinged chords and tight, angular lines. Peacock's playing reveals so much wood in his tone that it feels percussive -- despite his continual bluesy, swinging riffs and vamps. The title cut that closes the proceeding is crystalline, full of space, elegance, and grace. It sounds like the seamless interplay between the two is not improvised but composed and arranged. On Azure, the effortless communication between these players is like a conversation that is so intimate it can, at times, feel as if the listener is eavesdropping. Hopefully these two will be motivated to do this again.