Stewart was privileged to learn from many mentors during his schooling. His major choral teachers include Earl Rivers and Stephen Coker at the College-Conservatory of Music at the University of Cincinnati; Jonathan Talberg at California State University, Long Beach; Mack J. Wilberg, Ronald Staheli, and Rosalind Hall at BYU; William Hall at Chapman University; and Ted Reid at Fountain Valley High School. His piano teachers include Jeffrey L. Shumway and Irene Peery-Fox at BYU; Joseph Matthews at Chapman University; and Susan Bana in Orange, CA. His voice teachers include Randall Umstead at CCM and Clayne Robison at BYU. In addition, Stewart had the opportunity to study with a variety of conductors at CCM, including choral conductor and composer Dale Warland and instrumental conductors Mark Gibson and Ulrich Nicolai. His cognate studies in composition at CCM were with Shawn Okpebholo.
While attending CCM, Brett conducted the University of Cincinnati Men’s Chorus and co-conducted the CCM Chamber Singers. Prior to attending CCM he taught choir at Fountain Valley High School in Southern California for three years. In 2005 his choir took first place in the Golden State South choral competition.
Stewart also taught high school and middle school choirs at Meridian School in Provo, Utah from 2001-2002. That same year he was the assistant director and accompanist of the BYU Men's Chorus and Concert Choir under the direction of Rosalind Hall.
Stewart was an accompanist and assistant director for the Southern California Children’s Chorus under the direction of Lori Loftus from 1999-2000. He has also served in music callings for The Church of Jesus Christ of Latter-day Saints for sixteen years, including overseeing and directing choirs for sacred meetings and theatrical productions. He served as the co-chair on the Music Committee for the Newport Beach Temple dedication. Stewart was the music director for the Huntington Beach Interfaith Council’s first annual Procession of Light Ceremony in 2000 at the Huntington Beach Pier, where he conducted an interfaith choir of 300 singers and an orchestra to close the event.
In addition to conducting, Stewart enjoys singing, composing, and teaching piano. He has taught piano for seventeen years and has enjoyed composing and arranging for choirs and orchestras since his youth. He currently resides in Fountain Valley, California with his wife Mindy and their children Brooke, Landon, Chelsea, Clark, and Lilly.