The storyline for Which Witch was found in the witch finder's manual Malleus Maleficarum, and the original script was written by Adrian and Bjørnov's manager Ole A. Sørlie. The lyrics of the early concert versions were written by Helen Hampton and Roger Avenstrup, in collaboration with Adrian, Bjørnov and Sørli.
The material was constantly developed throughout a period of eight years, resulting in several national and international tours presenting continuously updated concert versions of the musical.
The Operamusical Which Witch opened at the Piccadilly Theatre in London on October 22 1992 and ran for 76 performances. The London version was followed by a hugely successful Norwegian tour, and further performances of a Norwegian version in Holmenkollen, Oslo during the summer of 1994.
Which Witch has, since its premiere in May 1987, been performed a total of 142 times in concert version in the following countries: Norway, Canada, USA, the Netherlands, England, Spain, Finland, Sweden and Denmark. The total attendance figure is approx. 276,000.
Total record sales are in excess of 110,000 units.
Licenced productions have been staged in several European countries.