[2][3] Gjerstad played in the trio Detail together with the British drummer John Stevens, in the period 1981–1994, and they released fourteen albums.

Other members of the band were the pianist Eivin One Pedersen (1981–82) and the mega bassist's Johnny Dyani (1981–1986) or Kent Carter (1987–1994).

In 1985, he initiated "Circulasione Totale Orchestra", a band with varying lineups, where young musicians, mostly from Stavanger, could get a chance.

He also collaborated with numerous musicians in various small groups, which has resulted in several albums, tours and festival recordings in Norway, United States and Europe.

The most long-lasting partnership in recent years is the current issue of Gjerstad Trio where he plays with drummer Paal Nilssen-Love and bassist Øyvind Storesund.