The best improvisers are the ones that seem to invent and uninvent their instruments right in front of your eyes and ears. Swedish pianist Sten Sandell and Norwegian drummer Paal Nilssen-Love are two musical champions with a long experience of doing exactly that. Jacana, the latest in Rune Grammofon's occasional series of unusual duo combinations, features the pair's sparkly improvised set captured at the 2013 Kongsberg Jazz Festival in southern Norway. Sten and Paal have been working together since forming a trio with Swedish bassist Johan Berthling (Fire!, Tape, etc.) in 1999, but this duet marks the start of a new chapter in their relationship. Jacana's three tracks find the players flying close to the limits of their comfort zones, sometimes resembling the strange formality of Asian court music. It's savage and ritualistic, spiky yet flowing, arrhythmic but surging with understated pulses. Sandell breaks into vocal overtones on "Kauri" like some tranced-out Mongolian shaman. He pokes around in the guts of Nilssen-Love's rough surgical cuts and, at the start of the track "Jacana" itself, pulls out some ear-bogglingly rubbery notes from his piano's deep innards. At the end of "Curvature" they break off from their instruments and simply clap for a while. Two men getting down to the essentials of what humans can do with wood, strings and skin. Sten Sandell is one of Swedish jazz's most distinguished elder statesmen, having worked unrelentingly since the mid-'80s. As well as his own trio and numerous international collaborations, his keyboard skills have been heard in groups such as GUSH, Guschwachs, Sven-Åke Johanssen Quintet, Townhouse Orchestra, and most recently, Mats Gustafsson's Fire! Orchestra. He has also composed music and sound art for installations, intermedia works, radio plays, theater and film. Paal Nilssen-Love is one of the most intense drummers working on the planet right now. In theory, he's based in Oslo, but there's a huge global demand for his percussive threshing machine. He's often travelling on a relentless round of musical projects and festival appearances -- notably with Mats Gustafsson in The Thing, his Chicago trio with Ken Vandermark and Ab Baars, the Hairy Bones group with Peter Brötzmann and Toshinori Kondo, a trio with Massimo Pupillo and noise-artist Lasse Marhaug, plus duos with Peter Brötzmann, Terrie Ex, John Butcher, and others. This duo is planned as an ongoing project, and offers some of the most refreshingly challenging music coming out of Scandinavia today. Jacana is another fine mess they've gotten themselves into. Sten Sandell (piano, voice); Paal Nilssen-Love (drums, percussion).