Sigur Rós
Kjartan has performed under the pseudonym "The Lonesome Traveller" with Sigur Rós bandmate Orri Páll Dýrason and Amiina violinist María Huld Markan Sigfúsdóttir (whom Kjartan married in 2001). "The Lonesome Traveller" covered Sigur Rós songs acoustically in an alt-country style.