Joni Mitchell may be more revered by jazz players than by her pop-music peers. Pianist Herbie Hancock is the latest acolyte, releasing River: the joni letters, a tribute disc that delivers at a high, innovative level. Hancock’s assimilation of the material is unexpectedly introspective. His performance—which boasts the now-requisite guest artists, including Norah Jones, Tina Turner and, surprisingly, Leonard Cohen, in addition to Mitchell herself—is one of the pianist’s best efforts.

Supported throughout by fellow Miles Davis sidemen Wayne Shorter on reeds and Dave Holland on bass, the trio lays down a mellow, almost ethereal groove with the help of guitarist Lionel Loueke and drummer Vinnie Colaiuta. Most interesting is “Both Sides Now,” which uses Mitchell’s original melody as mere seasoning in a truly engaging mix.