Azure is the first recording by the duo of bassist Gary Peacock and pianist Marilyn Crispell, a partnership that had toured for years without leaving anything on disc. Released by ECM in 2013, it sets eleven pieces between composition and free improvisation, played by two musicians who share a lyrical instinct and a long background in open, unscripted playing.

The two had already worked together in Crispell's trio with drummer Paul Motian, on the ECM albums Nothing ever was, anyway and Amaryllis. Azure was recorded in January and February 2011 at Nevessa Production in Saugerties, in upstate New York, where both musicians live. Chris Andersen engineered the session, and Peacock and Crispell produced it themselves. The programme is carefully balanced: three compositions by each player, three duo improvisations (Leapfrog, Blue and the title track) and one solo for each instrument.

Crispell's Patterns opens the album with knotty, fast-moving figures that she plays in unison with both hands, while Peacock shadows them, sprints ahead and stops short. Her Waltz After David M, at over nine minutes the longest track, is the most openly melodic music here, slow and clearly structured. Peacock's Lullaby rests on repeating chord progressions over which both players weave lines, and in his Puppets he takes a rare solo with the bow, pushing towards the outer edges of the instrument. Much of the rest moves away from a tonal centre without losing its lyricism, and the freely improvised Azure closes the disc, suspended and moving forward at the same time.

Reviewers heard the album as a meeting of equals. In The New York Times, Nate Chinen wrote that "the results are often starkly beautiful, with the sort of contemplative glow that only maturity seems to provide." John Fordham in The Guardian recalled Crispell as "an unruly free-jazz keyboard cyclone for years", now joining that command to delicacy and patience, and noted the deep standards vocabulary that Peacock, a cornerstone of Keith Jarrett's Standards Trio, brings even when song structures dissolve. For John Kelman of All About Jazz it was the most superb duo recording of its year.

This is the CD edition, ECM 2292, first released on 14 June 2013.