Liaisons: Re-Imagining Sondheim from the Piano is the recorded outcome of a commissioning project led by the American pianist Anthony de Mare. He asked 36 composers from seven countries to take a song by Stephen Sondheim and rethink it as a piece for solo piano. The contributors come from contemporary composition, jazz, film scoring and musical theatre, and their answers run from close paraphrase to free fantasia. Across three discs and 37 tracks, the set becomes a study of how much material one songwriter's melodies and harmonies hold.

De Mare plays every piece. The recordings were made between 2010 and 2014 at the American Academy of Arts and Letters and at Greenfield Recital Hall, Manhattan School of Music, both in New York. Judith Sherman was recording producer and engineer, and the release is an ECM production. The songs are drawn from twelve Sondheim shows, from A Funny Thing Happened on the Way to the Forum (1962) to Passion (1994). Among the composers are Steve Reich, Wynton Marsalis, Frederic Rzewski, Fred Hersch, Ethan Iverson, Mark-Anthony Turnage and Thomas Newman, and others. The booklet has texts by de Mare, Mark Eden Horowitz and Sondheim himself.

The first disc opens with William Bolcom's A Little Night Fughetta, which gives a Sondheim theme the gravity of Bach-style counterpoint. Reich's Finishing the Hat, after Sunday in the Park with George, is set for two pianos, both played by de Mare. It turns the song into a chain of insistent, stuttering chords. Duncan Sheik's Johanna in Space places the Sweeney Todd ballad over a backing track that Sheik supplied himself. Elsewhere Rzewski makes I'm Still Here into a reflective fantasia, and de Mare closes the set with his own encore on Sunday in the Park.

Reviewers mostly welcomed the scale of the idea. In the San Francisco Chronicle, Joshua Kosman found it thrilling to hear how much a Sondheim song offers another composer, and concluded: "The whole undertaking is a triumph." Geoff Brown, giving it four stars in Classical Music in 2016, judged a few pieces less successful but wrote that "the duds never seriously compromise the joy and diversity of De Mare's enterprise and artistry". Sondheim himself remarked that very few of the pieces are built like a song, and that they float freely, like fantasias.

This is the 3CD edition, ECM New Series 2470-72, released in October 2015.