He was a founding member of the Sugarcubes and has been a longtime fixture on the Icelandic punk and alternative music scene.

Other bands he has played in have included Þeyr, Kukl, Emiliana Torrini, Ben Frost, Kippi Kaninus, SJS BIGBAND, Headpump, Bradley Fish and the Reptile Palace Orchestra.

The two also had a percussion group called Parabolur from 2005, along with longtime collaborator Guðmundur Vignir Karlsson of Kippi Kaninus.

Sigtryggur also has a number of filmography-related accomplishments to his credit, including soundtracks for Rokland (Stormland) 2011, One Point O (2004) and Takedown (2000), acting as the Drummer in Monkey Drummer (2000) by English director Chris Cunningham,[2] and working as a sound recordist for an episode of the documentary television series Naked Science.

He has written music for theater productions in Iceland, namely Enron (2010) and Chekov's The Cherry Orchard (2011) in the Reykjavik City Theatre.