When Stefano Bollani, the dazzling Italian improvising pianist, sang a little grand opera with a Norwegian accordion player, it practically counted as medical attention for the drenched and windswept visitors to a town living up to its name in a big way. But the glow of the formidable Mingus Big Band also raised the temperature at this eclectic annual event, and so did that unstoppable octogenarian Stan Tracey, in an imperturbably thunderous duet with bassist Andy Cleyndert. Autumn Leaves, its melody sketched only as a series of raucous clues, was classic Tracey.

The duo of Bollani and Norwegian accordionist Stian Carstensen tore through flying tangos and variations on classical favourites that developed as improvisations across endless modulations: Dancing Cheek to Cheek gypsy-style, segues of Mack the Knife first into The Entertainer, then a Scottish reel, then a barn dance. Then the Mingus Big Band, that most uninhibited of tribute ensembles, mixed Mingus classics with the late composer's lesser-known pieces: the latter dramatically included Children's Hour of Dreams, from the posthumously discovered masterwork Epitaph.

In a strong Norwegian presence, pianist Christian Wallumrod's quartet (featuring the beautiful, flute-like trumpet tone of Arve Henriksen) took a sepulchrally trancelike approach - sometimes barely mobile, but its focus on the delicacies of timbre and nuance vibrates something very deep down: maybe it's the heartstrings. Former rock drummer Bill Bruford's duo with Dutch pianist Michiel Borstlap, by contrast, was busy, playful, frequently swinging and funky. They sounded a shade content with a kind of garrulous cleverness early on - but, as these conversations between good players do, it found a special space after a while and drew the audience into it.