
His compositions have been performed at festivals such as U.N.M. and has been performed by ensembles such as Quartet San Francisco (US), The Zapolski Quartet (DK), Atón (IS) by members of ensembles such as Poing (NO), Caput (IS).
Gudmundur Steinn was the musical director of an experimental animated film named Hidebound, which won a special price for music at the NUFF young film makers festival in Norway. He has also been active as an improviser and has performed in that context with musicians such as Steve Hubback, Fred Frith, Andrew D'Angelo, Ad Peijnenburg, Hilmar Jensson and Skúli Sverrisson.