Stefan Sand was born in Copenhagen in 1995. In 2017, he graduated as a pianist and piano teacher from the Royal Danish Conservatory of Music with Jens Elvekjær and Søren Rastogi. Since then, Stefan moved to Reykjavík, Iceland, where he was educated at Iceland's Academy of Arts as an innovative music mediator in the master's program "New Audiences and Innovative Practices" in 2021, and then as at the masters program in composition under ÚIfar Ingi Harraldsson, Hróðmar Sigurbjörnsson and Tryggvi M. Baldvinsson in 2023. Stefan has studied orchestra conducting privately with Frederik Støvring Olsen and at Iceland University of the Arts with Gunnsteinn Ólafsson, as well as choir conducting with Magnús Ragnarsson.

Stefan is focused on communicating music via collaboration with other types of art forms and artists, as his project Look at the Music has demonstrated in 2021-2023. The project was a close artistic collaboration between deaf and hearing people, where the goal was to create a concert experience that both hearing impaired, deaf, and hearing people could enjoy. This resulted in a concert tour in the Nordic countries in 2023 where many works were performed by sign language soloists and a chamber choir. The music in the project is composed based on sign language in various ways. This project earned him a nomination for Sproti ársins (Upcoming Artist of the Year) at Gríman, the Icelandic Stage Arts Award in 2024.

As a choir conductor, Stefan often writes music for choirs that he conducts himself, and although Stefan is newly graduated, he has already established himself as a composer and conductor in the Icelandic cultural scene and has written music for several choirs and soloists, including Iceland's University Choir, the Women's Choir Vox Feminae, Art Across Vocal Ensemble, Guðrún Jóhanna Ólafsdóttir, Hallveig Rúnarsdóttir and Ólafur Freyr Birkisson.

Stefan works as a freelance composer in Iceland and Denmark and conducts the choirs Vox Feminae, Hljómeyki and Mótettukórinn.