Justin Gruber began his musical endeavors on the tuba at the age of 9 and currently holds the Tuba position in the Winnipeg Symphony Orchestra. Justin's orchestral pursuit began in his junior year of high school when he won the Principal Tuba position in the Florida Youth Orchestra. He held this position for the rest of high school while traveling to Carnegie Hall in 2018 and the Midwest Clinic in 2019 with his prestigious high school wind symphony. Before leaving high school, Justin was a finalist in the New World Symphony Concerto Competition, a National YoungArts winner, and was awarded the Kovner Fellowship from Juilliard. 

He was then awarded the President's Music Scholarship to the University of Miami's Frost School of Music, where he studied with Dr. Aaron Tindall to pursue a bachelor's degree in music performance. In his first year, he won 3rd prize in the Leonard Falcone International Tuba Artist Solo Competition and became an Associate Member of the Chicago Civic Orchestra. Shortly after his summer in Greensboro, being an Eastern Music Festival Orchestral Fellow, Justin won the Principal Tuba position with the New Mexico Philharmonic performing their 2021-22 season. 

After his debut season, Justin attended the Brevard Music Festival as an Orchestral Fellow, where he was a finalist in the Jan and Beattie Wood Concerto Competition. Shortly after his time at Brevard, he was Principal Tuba with the Chautauqua Symphony Orchestra for the remainder of their 2022 season. Justin then went on to win the Principal Tuba position with the Winnipeg Symphony Orchestra. He is still completing his degree at Miami, with an estimated completion date of circa 2024, while maintaining his position with the orchestra. Justin is a 2023 Yamaha Young Performing Artist and was hand-selected as a Denis Wick Performing Artist in 2024. He was also awarded a fellowship to the prestigious Aspen Music Festival, where he will study with Warren Deck in the summer of 2023.

Justin is the new Low Brass Instructor at Sistema Winnipeg, an organization founded in 2011 that serves youth in Winnipeg, Manitoba, which is part of at-risk communities. He is currently a member of the Music Professionals of Manitoba. He continues to educate the next generation through his private studio, giving masterclasses to places such as Camp Arnes, the Manitoba Band Association, and the University of Manitoba.