Ontario Youth Choir Artistic Staff
Dr. Jean-Sébastien Vallée, Conductor
Jean-Sébastien Vallée is a renowned Canadian-American conductor, scholar, and pedagogue recognized for his expertise in vocal, choral, and orchestral repertoires. With a career spanning over several decades, Vallée has conducted numerous ensembles across North America, Europe, and Asia, and has collaborated with some of the world’s most prestigious orchestras including the Chicago and Toronto Symphony Orchestras, l’Orchestre symphonique de Montréal, and the National Arts Centre Orchestra in Ottawa.
Dr. Vallée is Artistic Director and Principal Conductor of the renowned 160-voice Toronto Mendelssohn Choir and the professional chamber ensemble, the Toronto Mendelssohn Singers. In addition, Jean-Sébastien is Full Professor of Music, Director of Choral Studies, and Coordinator of the Conducting & Ensembles Area at the Schulich School of Music of McGill University. He has previously served as the Director of Choral Studies at California State University, Los Angeles, and was on the choral faculty of the University of Redlands.
His discography includes several critically acclaimed recordings on the ATMA Classique label: Lux (2017), Requiem (2018 – Fauré and Duruflé), Distance (2021), and Remember (2024). Broadcast internationally, these projects reflect his dedication to both historical and contemporary repertoire.
Recent and upcoming engagements include performances at the Liszt Ferenc Academy of Music in Budapest, tours with the National Youth Choir of Canada and the 2026 Alberta Youth Choir, and collaborations with the National Arts Centre Orchestra, the Orchestre symphonique de Québec, the Tanglewood Festival Chorus, and the Boston Symphony Orchestra.
In recognition of his artistic leadership and contributions to the field, Dr. Vallée received the 2025 Distinguished Alumni Prize from Université Laval, awarded to alumni who exemplify innovation, creativity, talent, and exceptional leadership in their professional achievements.
Website: jsvallee.com
Dr. Irene Gregorio, Collaborative Pianist
Dr. Irene Gregorio enjoys a diverse and active musical life as a pianist, music director and educator. She has collaborated in recital with members of the LA Phil, San Francisco and Toronto Symphonies, and worked with choirs such as the Los Angeles Children’s Chorus, Ontario Youth Choir and National Youth Choir. Since 2020, she has served worked alongside Jean-Sébastien Vallée as pianist/musical assistant for the esteemed Toronto Mendelssohn Choir.
After 16 years in California, she returned to her hometown of Guelph, where she serves as the Director of Music Ministry at Dublin St. United Church, and Adjunct Professor of Piano at the University of Guelph, serving as chorusmaster for the UofG Symphonic Choir in their performance of the Mozart Requiem with the Guelph Symphony Orchestra in 2024. She also serves on the faculty of music at Wilfrid Laurier University as a collaborative pianist/coach. She has earned diplomas in organ and choral conducting from the Royal Canadian College of Organists, and is a graduate of the University of Southern California, University of Michigan and University of Western Ontario, where she earned the Gold Medal in Piano Performance.
She believes that music is a powerful agent for social justice, and has been actively involved in community outreach programs with groups such as Street Symphony in Los Angeles, a non-profit organization that creates musical connections with underserved and incarcerated communities in Skid Row and beyond. A proud Filipina-Canadian, she has served her community as a board member of the Centre for Filipino Studies and the Filipino-American Symphony Orchestra in Los Angeles. Her doctoral study centered around post-colonial perspectives of the Filipino art song form called the kundiman, and she intends to publish a performing edition of these works. In 2024, she founded the Pamati Children’s Choir of Guelph, a children’s choir that celebrates Filipino culture and music.
An avid foodie and beginner triathlete, she enjoys salsa dancing, latin jazz, languages, and loves to be with her family, husband Nicholas and two wonderful children, Kali and Lila. Her late brother, conductor and singer, Dr. Dominic Gregorio, was a tremendous force in her musical life, and she feels incredibly blessed to have a life in music, playing with colleagues and students, who are a constant source of beauty and inspiration.
Intern Conductors
Nathan Gritter, is a conductor and singer based in Toronto. He is currently the music director at Kingsway-Lambton United Church and sings professionally with the Elora Singers, Toronto Mendelssohn Singers, and the Trinity Bach Project. He is also a founding member of the new small professional ensemble Silver Thread. Nathan sang in the 2017, 2018, and 2019 sessions of the Ontario Youth Choir and was the Program Coordinator in 2022. He is thrilled to be returning to OYC as intern conductor and is excited to dive into a new musical adventure with the 2026 OYC.
Rocco Marciano, is a Toronto-Based conductor, pianist, and baritone. He is currently pursuing a bachelor of music degree at the University of Toronto, majoring in classical piano. Rocco is the director of music at Calvin Presbyterian Church, and an assistant conductor at St. Michael’s Choir School.
Yann McHaffie, Born and raised in Ottawa, Yann is currently an MMus student in choral conducting at the University of Alberta, under the supervision of Timothy Shantz and Adam Robertson. A pianist and choral singer from a young age, he has worked with choirs in both Ottawa and Edmonton, and is currently the assistant conductor for the University of Alberta Mixed Chorus. He is a proud alum of the University of Ottawa, where he completed the BMus/BSc program in piano performance and chemistry in 2025. When he’s not on the podium or running a sectional, Yann enjoys cooking, bartending, and playing video games.