Herbie Hancock is many things to many people.

Jazz fans regard him as an unparalleled institution of post-bop harmonic mastery. Peace-loving boomers recognize him as a foremost purveyor of funk. Gen-Xers know him as the one-hit-wonder behind the 1983 electronic dance hit, "Rockit."

Serious jazz fans need not fear that "River" is a return to the antiseptic pop of 20005s "Possibilities." The Hancock of "River" is the same Hancock who redefined the art of jazz piano as a member of the Miles Davis Quintet in the 1960s.

"River" is his deeply personal and honest response to Joni Mitchell's peerless oeuvre.

Hancock enlisted producer Larry Klein, a longtime musical collaborator and onetime husband of Mitchell's, to gain insight into the sometimes enigmatic lyrics.

Mitchell's words are delivered by a stellar cast of guest vocalists including Norah Jones, Tina Turner, Corinne Bailey Rae, Luciana Souza, Leonard Cohen and Mitchell herself. But this is no contrived all star media-event-in-a-box, as some considered "Possibilities" to be.

The drama of "River" lies in the intuitive relationship between straight-forward vocal deliveries and organically unfurling instrumental improvisations.

Nearly all of the vocalists act as foils to the band's deeply reflective playing. Norah Jones and Tina Turner both have thick, smoky voices that sail over Hancock's dissonant harmonic adventures in the first two tracks, "Court and Spark" and "Edith and the Kingpin." Brazilian singer Luciana Souza channels Mitchell's spirit superbly on the stark "Amelia."

Mitchell's own contribution on "Tea Leaf Prophecy" is, as expected, perfect. The band's tender accompaniment actually serves the song's sullen nostalgia better than Mitchell's original synthesizer-infused version.

Leonard Cohen's spoken-word reading of "The Jungle Line," accompanied only by the savage riffs of Hancock's piano, makes for a haunting end to a mostly somber record.

Though the vocal contributions may be the album's selling point, Hancock makes room for four instrumentals, two of which  "Both Sides, Now" and "Sweet Bird"  were originally vocal features for Mitchell. Some of the best playing happens on these two tracks.

Listeners may not easily hear the melody in Hancock's fragmented version of "Both Sides, Now," but should have little trouble identifying the world-weary poignancy of Mitchell's original version.

The band's reading of Shorter's "Nefertiti," the record's only modern-jazz standard, gets rowdier than any other track on the album, but steers clear of the post-bop athleticism ubiquitous in modern jazz performance.

Rather than use the asymmetrical melody as a jumping-off point for blistering solos, Hancock's band treats Shorter's tune as another page of poetry worthy of deep contemplation.

If only more jazz musicians played that way.