By the time he was 18, the drums eclipsed the piano as McLean's voice for musical expression and the age of 22 he was playing with fellow Canadian and jazz icon, Oscar Peterson.

McLean's recording and touring highlights include George Michael,[7] Gladys Knight, Joe Sample,[2] Jamie Cullum, Andy Bey, Molly Johnson, Peter Cincotti, Andrea Bocelli, Serena Ryder, Catherine Russell, Jane Bunnett, Billy Joel, Dionne Warwick and Michael Kaeshammer.

McLean has worked with many of jazz masters and pop icons, including Wynton Marsalis, Michael Feinstein, Billy Joel, Quincy Jones, Gladys Knight, Diana Krall, Glen Campbell, Carla Cook, Linda Eder, Jimmy Webb, Vanessa Williams, Patti Austin, the Backstreet Boys and producer Phil Ramone.

He also served as arranger[13] on Molly Johnson's 2009 Juno-award-winning album Lucky, and was co-arranger[14] on Sophie Milman's 2009 release Take Love Easy, while continuing to tour and record as a member of George Michael's band.

Producer Phil Ramone following a recording session with Billy Joel remarked: "Mark McLean is a tasty, sure handed drummer, a song man’s musician.

"[10] Andy Bey described McLean as "an intelligent, immensely talented young musician with a curious mind and a listening ear.