Stewart was born in Ohio and currently lives in a small New Jersey town just outside New York. He studied piano with a number of teachers in his youth, most notably Margaret Baxtresser in Akron, Ohio. A short music career ensued, mostly in musical theatre, the greatest result of which was his marriage to singer Susan Gempler. Having achieved his goal of finding a spouse, he employed his math education to get into software development. This has been a good career for him for 20 years, having made it possible to him to get a decent piano, among other things.
An avid amateur, Stu plays daily and performs occasionally. Other hobbies include gardening, hiking, beer brewing and cooking.