Jon Ivar Christensen (20 March 1943 – 18 February 2020)[1] was a Norwegian jazz drummer.

[4] In the late 1960s, Christensen played alongside Jan Garbarek on several recordings by the composer George Russell.

He also was a central participant in the jazz band Masqualero, with Arild Andersen, and they reappeared in 2003 for his 60th anniversary.

[5] He appears on many recordings on the ECM label with such artists as Keith Jarrett, Jan Garbarek, Terje Rypdal, Bobo Stenson, Eberhard Weber, Ralph Towner, including the seminal 1975 Solstice, Barre Phillips, Arild Andersen, Enrico Rava, John Abercrombie, Michael Mantler, Miroslav Vitous, Rainer Brüninghaus, Charles Lloyd, Dino Saluzzi Jakob Bro, and Tomasz Stanko.

[6] Christensen was a member of the Keith Jarrett "European Quartet" of the 1970s, along with Jan Garbarek and Palle Danielsson, which produced five jazz recordings on ECM Records.