At age 10, Gelin taught himself to play the trumpet simply by emulating his favorite records. After years of self-tutelage, Adrian D’Aguilar, bass player, began to mentor him; thereby, providing him the tools to play jazz. In 2017, the Nassau-born trumpeter would study with Dr. Eddie Henderson at the Oberlin Conservatory. The same year, he received recognition at the Young Arts Foundation and Betty Carter Jazz Ahead Program. Thereafter, he continued his studies at the Juilliard School --- graduated June 2021.