Clark grew up in a jazz environment as the son of Stan Tracey CBE, the UK's leading jazz pianist, and from an early age took to the piano and vibraphones. At 13 he started playing the drums and he turned professional at 17 in 1978 by joining his father's various ensembles, from trio to orchestra up to the present day. Within that context he has toured worldwide and recorded extensively. In 2001 Clark began his own record company, Tentoten Records and in 2007 he formed Resteamed Records, a label dedicated to his father's works. In 2017 he wrote a biography of Stan entitled "The Godfather of British Jazz", released on Equinox Publishing.

In 1981 he formed the first of his own groups with Django Bates, & Iain Ballamy. Later groups have included Guy Barker, Nigel Hitchcock, Dave O'Higgins, Mark Nightingale, Mornington Lockett, Julian Arguelles, Gerard Presencer, Alec Dankworth, Simon Allen, Zoe Rahman, Arnie Somogyi, Lewis Wright, Kit Downes and Chris Maddock. His latest band of luminaries features Alexandra Ridout and Sean Payne.

He has received commissions for his quintet, an octet called “Bootleg Eric” shared with pianist Dave Newton, "Continental Drift" (an 11 piece band co-composed with Stan Tracey and commissioned by The Arts Council), and composed for the Berkshire Youth Jazz Orchestra and the Appleby Festival big band. He has also written string quartet arrangements for his own group and vocalists Claire Martin & Joan Viskant, also the folk group Filska. He composes & arranges for his own groups too.

Clark has had 40 years' experience playing alongside some of the most important artists in jazz at home and abroad. Some of the most significant unions with American artists have been with Johnny Griffin, Pharaoh Sanders, John Hicks, George Cables, Bud Shank, Red Rodney, and Scott Hamilton. British artists include names such as Ronnie Scott, John Surman, Alan Skidmore, Kenny Wheeler, Alan Barnes, Don Weller and Tommy Smith. He has recorded over 100 albums (15 as a leader) and performed in over 50 countries. He has been awarded "Best Drums" title six times in the British Jazz Awards (most recently in 2018) and Ronnie Scott's Award for "Best Drums" in 2007. He has endorsements with Zildjian Cymbals, Vic Firth Sticks, Remo Drumheads and Cambridge Drums. Clark also teaches privately and has given masterclasses at Leeds College of Music, Royal Academy of Music, Musicians' Institute of London, Bracknell jazz weekends courses, the Southport and Cheltenham festivals as well as numerous workshops around the UK and overseas, attached to British Council tours. He was for some years employed by the Hertfordshire Music Services. In 2012 he released an instructional book for Schott Publishing, "Exploring Jazz Drums". Since 2012 Clark has been a Visiting Tutor at the Royal Birmingham Conservatoire.

Clark has appeared on TV and radio all over the world, but key moments include "Omnibus" (BBC) with his quintet, "Mercury Music Awards" (BBC) with Sting, "Father & Son" (ITV) with own group and Stan Tracey, "The Paradise Club" (ITV), "Ellington's" (ITV), "Call Me Mister" (ITV), "Blue Note's 50th Anniversary Concert" with Tommy Smith at the Montreux Jazz Festival, plus numerous radio broadcasts with his own groups on Radios 2 & 3. In 1999 Clark had a feature in the motion picture "The Talented Mr. Ripley" starring Matt Damon, Gwyneth Paltrow and Jude Law and he performed on the soundtrack of the motion picture "Alfie" starring Jude Law. Clark has appeared on stage as an actor/drummer on three occasions; Last Chance Theatre Company's "The Last Connection" for 6 months, "Lady Day" starring Dee Dee Bridgewater for a year and "Lenny" starring Eddie Izzard and directed by Sir Peter Hall for a year.

In 2010 Clark revived Herts Jazz Club which was about to retire after 40 years. Since then Clark has promoted weekly gigs featuring a wide variety of musicians, young, established, British, American, international, and in 2011 started the first annual Herts Jazz Festival. Since 2009, Clark has taken over the running of , a jazz club in Hertfordshire originally formed in 1969. The club runs on a weekly basis over nine months of the year, promoting the best of jazz in the UK and presenting young groups as well as established groups. Herts Jazz also has an annual festival at which British jazz legends have appeared as well as overseas artists.