Marc Gelfo grew up in the sunny town of Vero Beach, Florida, where he first studied piano, violin, cello, and finally, was captivated by the unique sound of the horn, which he played throughout middle school and high school. He attended Northwestern University to study cognitive science, computer science, and Chinese, graduating in 2004.

Afterwards, Marc returned to his passion for music and enrolled at Indiana University to study horn performance and audio engineering. While at Indiana, he studied with Myron Bloom, Michael Hoeltzel, Richard Seraphinoff, and Jeff Nelsen, and was a participant in the Aspen Music Festival.

Marc spent 2006 and early 2007 performing with the Macao Orchestra and the Orquesta Sinfonica de Navarra in Spain, and he later became a full-time member of the Macao Orchestra. He joined the Hong Kong Philharmonic in 2008. In addition to classical music, Marc performs jazz, funk, and experimental/electronic music on the horn and has been a part of several improvisatory collaborations.