Mary Esau studied history of musical theatre in England and the United States prior to studying musical theatre in Canada. Mary Lois Esau earned a B.F.A. at the University of Lethbridge in 1990 and a Master of Arts degree in the Department of Theatre at the University of Victoria in 1993.

Esau discovered the name of Salmon Arm’s John Leonard in the Book History of Music in British Columbia: 1850-1950 by Dale McIntosh and began searching for Leonard’s operettas. Leonard was a writer of original operetta material and quite possibly British Columbia’s first composer of light opera. Leonard wrote works specifically to meet the needs and abilities of his singers and actors. Deciding Leonard was a subject worthy of further research, Esau set out to write her Master’s thesis on Leonard’s career in music, calling it John F. Leonard and His High School Operettas.