He was raised in the nearby suburban community of Inwood, New York by his mother, Leah, a drummer, gown maker and bookkeeper.

Hart would later recall that many champion rudimental drummers attended his high school; this inspired him to ascend to the first chair in the All State Band as a pupil of Arthur Jones, who served as a father figure to him and ensured that he was not suspended for neglecting his other classes.

[2][3] While employed as a soda jerk at El Patio, a jazz club in Atlantic Beach, New York, he was influenced by Tito Puente's regular appearances.

During a tour in Spain, he reportedly sat in with a variety of notable jazz musicians (including Gerry Mulligan and Count Basie) in addition to performing in various ensembles (spanning the gamut from small jazz combos to marching bands) and on recording sessions for local pop stars.

[citation needed] Following his 1965 discharge, Hart briefly returned to the New York metropolitan area, where he filled in for the regular drummer in a "staid fox-trot band" as a member of the local musician's union.

[7] While stationed in southern California, he had discovered that his father (by now employed as a savings and loan association executive in Los Angeles) was still involved in the drumming community as an endorser for Remo.

[citation needed] By the end of the year, Hart had moved in with Michael Hinton, a student and friend who would accompany him to a Count Basie Orchestra performance at The Fillmore in mid-1967.

His interests in polyrhythmic rudiments and exotic percussion were integral to the band's arrangements in the period that archivist Dick Latvala would subsequently characterize as the "primal Dead era" of 1968–1969.

Two additional solo albums (including an ambient music project that was envisaged as the soundtrack for The Silent Flute, a screenplay co-written by Bruce Lee, James Coburn and Stirling Silliphant that was ultimately filmed in 1978 as the David Carradine vehicle Circle of Iron) were completed but rejected by Warner Brothers due to the label's increasingly strained relationship with the Grateful Dead.

[10] Hart's home recording studio proved to be a haven for the more idiosyncratic endeavors pursued by various band members, and he continued to collaborate with his former bandmates on various projects, most notably Robert Hunter's Tales of the Great Rum Runners (1974) and Ned Lagin's Seastones (1975).

In the 1996 Furthur Festival, Mickey Hart's Mystery Box played, as did Bob Weir's band, Ratdog.

The Rhythm Devils announced their first tour in 2006, which ended at the popular Vegoose festival in Las Vegas, Nevada over the Halloween weekend.

The final result will be a "musical history of the universe", from the Big Bang onwards through galaxy and star formation, up until modern times, including images from the Hubble Space Telescope and rhythms derived from the cosmic microwave background radiation, supernovae, quasars, and many other astrophysical phenomena.

[20] In April 2010, it was announced that Rhythm Devils will tour in the summer of 2010 with a new line-up including Hart and Bill Kreutzmann (assorted percussion), Keller Williams (guitar, vocals), Sikiru Adepoju (talking drum), Davy Knowles (guitar, vocals), and Andy Hess (bass).

This version of the band was Hart, Kreutzmann, Keller Williams, Sikiru, Steve Kimock and Reed Mathis of Tea Leaf Green on bass.

[23] This lineup included Tim Hockenberry (vocals, keyboards, trombone, saxophone, other instruments), Crystal Monee Hall (vocals, guitar, hand percussion), Ben Yonas (keyboards), Gawain Mathews (guitar), Sikiru Adepoju (talking drum, djembe, shakers), Ian "Inkx" Herman (drums), Greg Ellis (percussion), Vir McCoy (bass).

[27] On September 29, 2013, the completed version of his and George Smoot's film Rhythms of the Universe premiered at the Smithsonian Air and Space Museum in Washington, D.C.[28] In the summer of 2015, the surviving members of the Grateful Dead (Bob Weir, Phil Lesh, Bill Kreutzmann and Mickey Hart), joined by Trey Anastasio, Bruce Hornsby and Jeff Chimenti, performed a series of concerts to celebrate the 50th anniversary of the Grateful Dead.

In 2017, he released RAMU, which featured contributions from both his long-time collaborators Steve Kimock and Sikiru Adepoju as well as Avey Tare and Tank Ball, among others.