Terje Jensen had played guitar for several years before he met Kim Hansen, a glowing music lover with an exceptionally talented for that peculiar. Hansen neither song or played an instrument, yet he struck up with Terje to start band "Frosk". Among the other members were Bent Bredesen (guitar), Olaf Hjellum (vocals), Øyvind Kristensen (bass) and Tom Knutsen (drums). Kim became manager. "Frosk" played progressive rock clubs in and around Oslo, but after a while it stopped when Bredesen decided to start his own band and with Øyvind´s brother Erik Kristensen as a new guitarist.
Autumn 1972 "Frosk" disillusioned and on the verge of dissolution. Before a gig at the jazz club "Loftet" in Drammen, found the band that they should do something absolutely crazy. They painted themselves in faces, dressed in colorful, daring costumes and adopted their own pseudonym: Terje Jensen was Angelo Vittore, then Jonas Fjeld. Øyvind Kristensen became Eple Skrott, while his brother Erik was Hermann Normann. Tom Knutsen was Tom Metal, Olaf Hjellum was Brunulf Bølle and Kim Hansen decided to be Herodes Falsk.
The new band name was Jonas Fjeld Jazz´n´Rolf Band, inspired by books about the blond giant Jonas Fjeld authored by Øvre Richter Frich. Even Kim attended the scene, wearing plastic saxophone and daring woman underwear. And then something happened that no one thought possible: The show was a success. The band had to make several similar shows.
Jonas Fjeld´s first recording contract was with the Jonas Fjeld Rock´n´Rolf Band, a comedy band which included Herodes Falsk, in 1972. JFRRB played rock cuts, partly inspired by artists such as Frank Zappa and Captain Beefheart, and otherwise made themselves conspicuous by their theatrical stage show.
JFRRB became a household name in the music of Norway, but the big sales numbers failed to materialize, and the band felt that they were not focused on the label. So they gave in 1976 vehicle record "Finally (Uff, ikke nå igjen)" in the hope of being fired from the contract, but instead gave the band an unexpected breakthrough. "Finally" was the band´s decidedly top-selling album, reaching 15 place on the charts and gave JFRRB a piston humor band.
The Mountain and the rest of the band, however, wanted to be taken seriously as musicians, and distanced himself from "Finished" and stamp piece band. In 1977 the group was renamed Jonas Fjeld Band while Herodes Falsk left the group and formed Prima Vera. Jensen rated at this time to go back to using his real name, but chose not to do so since Jonas Fjeld had become an established name in Norwegian music. Jonas Fjeld Band characterized by blues influenced country rock.