Leckie began work at Abbey Road Studios on 15 February 1970 as a Tape-Operator, later graduating to Balance Engineer. During this early career he worked with artists such as John Lennon (John Lennon/Plastic Ono Band), George Harrison, (All Things Must Pass), Syd Barrett (Barrett) and Pink Floyd (Meddle and Wish You Were Here). With Paul McCartney's Wings Leckie worked on Red Rose Speedway and the single "Hi, Hi, Hi". He mixed Be-Bop Deluxe's début album Axe Victim. His first job as producer was the same band's third album Sunburst Finish, which collaboration continued through Modern Music, Live! In The Air Age and Drastic Plastic.
Leckie left Abbey Road in 1978 and produced albums for Simple Minds (Life in a Day, Real to Real Cacophony and Empires and Dance) and Magazine (Real Life). For Be-Bop Deluxe founder Bill Nelson, he produced the Red Noise album Sound on Sound and Nelson's subsequent solo album Quit Dreaming And Get On The Beam (the latter unreleased until 1981). Leckie recorded the début single, Public Image for Public Image Ltd. Leckie's work with XTC included 3D-EP, as well as the band's later albums: White Music, Go 2, 25 O'Clock and Psonic Psunspot which XTC issued under the pseudonym The Dukes of Stratosphear.
Album productions in the 1980s included work with The Fall, Brix Smith's post-Fall project The Adult Net, The Lucy Show, The Doctor's Children, Gene Loves Jezebel, Bill Nelson, The Posies, The Dukes of Stratosphear, and Let's Active. For some of his work with The Dukes, The Adult Net and The Doctor's Children, all bands that had strong 1960s psychedelic overtones, Leckie adopted the pseudonym 'Swami Anand Nagara'.
In 1989 Leckie produced The Stone Roses' debut album The Stone Roses. The album was voted the best record of all time on a music poll taken by BBC Radio 6 Music and features as Number 1 on the Observer Music Monthly’s June 2004 “100 Greatest British Albums”.
Notable production credits from this era include The Trashcan Sinatras' 1990 debut album Cake, Robyn Hitchcock and the Egyptians' 1991 album Respect, the Stone Roses' album Second Coming, The Lilac Time's And Love For All, Ride's 1993 (Carnival of Light), Elastica's 1994 eponymous debut album, Cast's albums All Change (1995) and Mother Nature Calls (1997), Kula Shaker's debut K (1996), and The Verve's A Storm in Heaven. In 1995, Leckie worked on Radiohead's album, The Bends. This would be the band's last album not to be recorded in full by Nigel Godrich, an assistant engineer present during Leckie's work on The Bends.
In 1999 he produced the début album Showbiz for Taste Media’s then new signings Muse. This went platinum on the heels of the band's breakthrough 2001 second album Origin of Symmetry, also produced by Leckie, which reached No. 3 in the UK album Chart. In 2000 he began production on "Wildflowers" the debut album from Northern Ireland band Relish. It attained platinum status in Ireland on release in 2001. In 2002, Leckie produced a single for Suede (Positivity from the album New Morning).
In 2009 he travelled to Mexico to work again with Rodrigo y Gabriela on tracks for the album 11:11. Leckie then returned to Abbey Road to record and produce the jazz sounds of Portico Quartet and was also called in to remaster the Anniversary Edition Box Set of The Stone Roses eponymous first LP complete with his videos of the sessions and some long lost demos. Leckie also appeared in TV's Classic Album Series playing and commenting on tapes from Plastic Ono Band sessions he had worked on some 40 years previously at Abbey Road Studios. In 2010, Leckie produced The Coral's album, Butterfly House. which went on to win Album of the Year at Music Producer's Guild Awards.
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- TMV Video Interview – John Leckie, Record Producer
- Video Interview with John Leckie, Record Producer