Five years have passed since the last album by the long-running UK postbop-to-fusion quartet Partisans, a powerful outfit that attractively mingles Wayne Shorteresque sax melodies (from the sophisticated Julian Siegel), seamless conjunctions of rock and bebop guitar (from Phil Robson, at his fluently swinging and melodic best here), and punchy groove-playing. Swamp sustains the band’s fondness for pieces on which styles shift, time signatures are rapidly juggled, and the resourceful Siegel and Robson cruise through multi-chorus improvisations; but a new batch of compositions widen the idiomatic sweep, and the soloing sounds even more assured. There are Afro-Caribbean dances that turn into jazzy wriggles and then crunching guitar rock; slowly winding guitar and bass clarinet melodies that build to garrulous polyphonies; and a sinister slow fusion powered by Thad Kelly’s bass-guitar that gets gradually funkier. It’s the 2014 edition of the signature Partisans method, but it’s still in fine working order.