McNair started out at the Alpha Boys School under the tutelage of Victor Tulloch, whilst playing with Joe Harriott (a lifelong friend who considered McNair his de facto younger brother), Wilton 'Bogey' Gaynair, and Baba Motta's band. He spent the first decade of his musical career in The Bahamas, where he used the name Little G for recordings and live performances. His early Bahamian recordings were mostly in Caribbean musical styles rather than jazz, in which he sang and played both alto and tenor saxophone. He also played a calypso singer in the 1958 film Island Women. In 1960, he went to Miami to record his first album, a mixture of jazz and calypso numbers entitled Bahama Bash. It was around this time that he began playing the flute, which would eventually become his signature instrument. Initially he had some lessons in New York, but he was largely self taught. He departed for Europe later in 1960.
Like many other West Indian jazz musicians of the 1950s and 1960s (eg Harriott, Dizzy Reece and Harry Beckett), McNair moved to Britain. However, before arriving in London, he toured Europe with Quincy Jones and worked on film and TV scores in Paris. Once in London, he quickly gained a reputation as a formidable player on flute, alto and tenor saxophone, leading to a regular gig at Ronnie Scott's nightclub.
His playing drew the admiration of bass player Charles Mingus, who was in London to shoot the 1961 motion picture All Night Long. McNair was part of a quartet Mingus formed to rehearse with during his stay in Britain. Unfortunately, the band never played live in front of a paying audience, due to a ban imposed by the UK Musicians' Union on US musicians in British nightclubs. A recording of the band exists, playing the earliest recorded version of the now famous Mingus composition Peggy's Blue Skylight, but it has never been released, despite featuring in the movie itself. The Musician's Union ban was lifted later in 1961, leading to a residency by US tenor saxophonist Zoot Sims at Ronnie Scott's club. Ironically, McNair's own quartet were also on the bill, resulting in two of his performances appearing on the album made to commemorate the gigs, Zoot Live at Ronnie Scott's. Around the same time, he also recorded with the drummer Tony Crombie and the percussionist Jack Costanzo.
McNair briefly returned to The Bahamas, where he cut his first all jazz LP Up In The Air With Harold McNair, before settling back in London permanently. His first UK album as a leader, 'Affectionate Fink', was made for the fledgling Island Records in 1965. The session saw him team up with Ornette Coleman's then current rhythm section of David Izenzon (bass) and Charles Moffett (drums), for a set of standards played with hard swinging intensity. McNair equally featured his tenor sax and flute on this session, delivering virtuoso performances on both. His next (self titled) album, cut for RCA in 1968, was another classic and featured probably his most famous composition, 'The Hipster', which has become a perennial fixture on the playlists at jazz clubs and was included on Gilles Peterson's Impressed Vol.2 compilation of 1960s British jazz.
His next album was 1970's Flute and Nut (RCA), which featured big band and string arrangements by John Cameron. This was quickly followed up in the same year by The Fence, which moved in the direction of jazz fusion. Another self-titled album was issued posthumously by the B&C label in 1972, which mixed tracks from the 1968 RCA album with later, unreleased recordings. Notable recorded works as a jazz sideman included sessions with the jazz-rock/big band ensemble Ginger Baker's Air Force and John Cameron's Off Centre. He also recorded with visiting Americans including vocalists Jon Hendricks and Blossom Dearie, drummer Philly Joe Jones and saxophonist Eddie "Lockjaw" Davis.
1) The Umbrella Man
2) The Night Has A Thousand Eyes
3) You Are Too Beautiful
4) Barnes Bridge
5) Nomadic Joe
6) Herb Green
7) My Romance
8) Burnt Amber