During this time he took in private lessons with Mick Goodrick, Jerry Bergonzi, and Hal Crook.

As sideman he has collaborated with Tim Berne, Wadada Leo Smith, Kevin Drumm, Herb Robertson, Trevor Dunn, Greg Bendian, Chris Speed, Briggan Krauss, Jamie Saft, Cuong Vu, Rafael Toral, Carlos Zingaro, Tom Rainey, Ben Perowsky, Per Jørgensen, Eyvind Kang, Arve Henriksen and Ståle Storløkken, among others.

[1] In 1999 Jensson joined Jim Black in the band AlasNoAxis.

In 2001, he founded the New York band 'Tyft' together with Jim Black and Andrew D'Angelo.

He also was also a founding member of the artist collective Kitchen Motors, an Icelandic that also acts as a record label.