John turned professional in 1987, moved to London and played all over the UK and Europe with Roy Williams, Enrico Tomasso, Warren Vache, Leroy Jones, Jon Erik Kellso, Scott Robinson, Mike Owen, Pete Rudeforth, Keith Nichols, T.J. Johnson, Amy Roberts, Stephanie Trick, Digby Fairweather, Jamie Brownfield, Molley Duncan, Tom Kincaid, Brian Kellock, Forrie Cairns, Jim Fryer, Ian Bateman, Emmet Cohen, Bryan Carter, Jim Douglas, Tony Pitt, Harry Beckett, Alan Skidmore, Jim Mullen, Zoe Rahman, Stan Sulzmann, Dave Cliff a.o.

In 1989 John won the prestigious NFMS Special Concert Artists Award and in 1993 attended Berklee School of Music in Boston, Mass. where he studied under George Garzone as well as privately with Jerry Bergonzi.
In 1994 john moved to San Francisco, where he studied privately with Joe Henderson before returning to London in 1995 where he continued touring Europe, US, Canada, North Africa and The Middle East before moving back to the US in 1998 to Seattle where he again studied this time with Don Lamphere before settling in Vancouver, B.C.

John has recorded 14 albums as a leader and well over 100 sessions for various jazz, pop, electronica and rock acts and has played sessions on the BBC Radio, BBC TV, STV,Radio Forth, Radio Clyde and Channel Four. Since returning to UK in 2005 he has toured with The Maveriks, Right Said Fred, Camille O’Sullivan, Scottish Opera, The Peatbog Fairies, Bill Wells and Aidan Moffat, Tam White and Blue Soul Groove.

In the last few years John has returned to his roots and his beloved New Orleans/Chicago jazz and spends most of his time playing music from the Golden Age of Jazz with the Louisiana Ragtime Band,  The Ugly Bug Ragtime Three and alongside Roy Williams and Enricco Tomasso in "Remembering Alex Welsh"