He joined Sextettinn (Sextet) (1977) when he was at University. He joined Sveinbjörn Baldvinsson (guitarist), Gunnar Hrafnsson (bass), Stefán Stefánsson (saxophone), Guðjón Hilmarsson (drums), and Kristín Jóhannsdóttir (vocals). The music of Sextettinn was original themes performed in several different styles from country-rock and pop-rock to pop-jazz. Sextettinn gigged throughout Iceland and had a presentation at the local TV station. Guðlaugur stayed for a short time, as his studies were taking most of his time. The remaining members of the group continued under a different name: Ljósin í Bænum, (The Lights of the City) and released an album still popular in Iceland.