He began playing guitar when he was thirteen, influenced by guitarists Les Paul and Barney Kessel.

In 1981, ahead of his debut in the U.S. as a leader, The New York Times stated, "Mr. Stewart seems to have his musical roots in bebop.

He leans toward material associated with Charlie Parker and he spins out single-note lines that flow with an unhurried grace, coloured by sudden bright, lively chorded phrases.

His up-tempo virtuosity is balanced by a laid-back approach to ballads, which catches the mood of the piece without sacrificing the rhythmic emphasis that keeps it moving.

"[4] Stewart was prominently featured in Norman Mongan's book, The History Of The Guitar In Jazz,[5] in a chapter devoted to guitarists who were considered to be contemporary masters (along with players such as Jim Hall, Pat Martino, and George Benson).