Billy Hart is a creative player most at home playing advanced jazz. He worked early on in Washington, D.C. with Buck Hill and Shirley Horn, and was with the Montgomery Brothers (1961), Jimmy Smith (1964-1966), and Wes Montgomery (1966-1968). Hart was a member of Herbie Hancock's challenging sextet (1969-1973), and played regularly with McCoy Tyner (1973-1974) and Stan Getz (1974-1977), in addition to extensive freelancing (including recording with Miles Davis on 1972's On the Corner). On his own, Hart has led interesting dates, including such albums as 1977's Enchance, 1987's Rah, 1993's Amethyst, 2006's Quartet, and 2011's La Place Demon & Sixty-Eight. In 2012, Hart delivered his ECM debut with All Our Reasons, featuring pianist Ethan Iverson, saxophonist Mark Turner, and bassist Ben Street. The group remained together as a touring and recording unit, issuing the follow-up, One Is the Other, in March of 2014. The same year he worked in Denmark with Niels Vincentz, Cameron Brown, and Tom Harrell on the album Is That So? on Stunt. 2015 saw him participated in a collaborative date entitled Five & Six under Ricardo Zenga's leadership alongside Gabriele Evangelista and Marco Allocco.
Hart was honored by being chosen to lead the WDR Big Band on the album The Broader Picture for Enja. He is also a member of the Jon Ballantyne Trio whose recording, Loose, was issued by Justin Time. Hart returned to ECM in Aaron Parks' trio with Street for 2017's Find the Way. The album was inspired, according to the pianist, by the recordings of Alice Coltrane and Shirley Horn (the latter of whom Hart played with) due to the emphasis both artists placed on space and subtlety.