Birgir Steinn Theodorsson started learning brass at a young age. Learned, among other things, tuba, horn and trumpet. During his teenage years, rock and pop music began to have a great influence, and as a result he began to learn the electric bass. Birgir was then in several bands as an electric bass player and gained a lot of experience playing for people, among other things, by playing at mass every Sunday for years. However, it wasn't until late adolescence that Jazz began to take over, and with it the instrument the double bass. Birgir Steinn moved to Denmark with his family and began to learn the double bass. When he got back home, he went straight to FÍH and he completed his final exam there in the spring of 2015. After FÍH, he went to Berlin for graduate studies. He also spent a year in New York, where he studied music. Birgir Steinn has a lot of experience with performing in concerts and recordings. He now teaches electric and double bass at Garðabær Music School and Reykjanesbær Music School, as well as playing various gigs and recording bass in various projects.