Stefán R. Gíslason began his musical studies at the Skagafjörður Music School. Further studies followed at the Akureyri Music School where he took a final exam in organ playing and at the State Church Music School where he studied vocal training and choir conducting. He has been the choir conductor of the Heimir Men's Choir since 1985 and has taken the choir on many concert tours, both abroad and in Iceland. Under his tenure the choir has also released four CD's that have all been met with great enthusiasm.

Stefán is the assistant principal of the Skagafjörður Music School and is also the church organist for Glaumbæjar-prestakall. He has been involved with organising various musical events in Skagafjörður throughout the years and has appeared as an accompanist with many artists and ensembles, most notably the popular Álftagerðibræður male quartet.