The core of the band are the brothers and the main songwriters, Lars and Martin Horntveth. Martin formed Jaga Jazzist together with Ivar Christian Johansen in 1994 while they still were in their teens, though Johansen later left the group. The brothers are also prominent figures of the Norwegian pop act The National Bank.
Jaga Jazzist nearly created a sensation with their debut album Jævla Jazzist Grete Stitz (1996), that contained playful, humorous jazz with elements of rap. The EP Magazine (1998) showed signs of the catchy, cinematic approach to jazz music they later became known for. The very young Lars Horntveth became increasingly involved in composing the music they played.[1]
After Magazine word spread about their fresh musical expressions and energetic live shows, and the band toured extensively before they signed a recording contract with Warner Music of Norway in 2000. The highly anticipated debut album for Warner, A Livingroom Hush, was released in 2001 and consists of a melodic and energetic mix of lounge jazz, cinematic themes and instrumental rock. The producer Jørgen "Sir Duper Man" Træen played an important role during the recording, and left his mark on the disc with his crackling electronics. A Livingroom Hush won the Norwegian music award Alarm Prize in 2002 and the same year was named Jazz Album of the Year by BBC listeners.
"That Live with Britten Sinfonia was an album not necessarily intended to happen at the time of the recording only makes its release all the sweeter. This 35-piece marriage of Jaga Jazzist and Britten Sinfonia is capable of everything from earth-shattering power to refined beauty. With Britten conducted by Christian Eggen, Live with Britten Sinfonia is the vital document of an opportunity that no longer need feel missed by so many Jaga fans around the world—an album that, transcending their already significant accomplishments, demonstrates even greater potential for Lars Horntveth's writing and Jaga Jazzist's effortless (and faultless) performances."[6]
Jaga Jazzist released their album Starfire in 2015 on Ninja Tune.