Two's company, three's a crowd doesn't really apply to this unique trio session recorded live in concert by Danish saxophonist Lotte Anker along with two pianists, fellow Dane Jacob Anderskov and Pole Kamil Piotrowicz. Actually one 49-minute improvisation, divided into tracks named by each letter of the title, it's a fine showcase for Anker's in-the-moment creativity on soprano, alto and tenor sax. Anderskov and Piotrowicz, both of whom lead their own groups, use the dual piano's 166 keys to provide the melodic and rhythmic functions of a whole band.

Dynamic and surging and usually evolving from andante to prestissimo, the flowing exposition has one pianist frequently advancing measured and echoing tones, while the other creates a pile up of juddering key clips and continuous rumbling strokes. Alternately harsh and heraldic, Anker's contributions undulate up and down the scale from foghorn-like honks and droning snarls to triple-tongued squeals and altissimo projections.

Although there are interludes of balladic quiet and mid-range motion, often advanced by the pianists' pedal point vibrations and elevated tinkles, they merely underline the program's controlled intensity. Climax is reached during the penultimate sequences as Piotrowicz and Anderskov concentrate their keyboard clips, clanks and clunks into a contemporary version of a boogie-woogie duo. Meanwhile Anker note bends to emphasize irregular vibrations, squeaking breaths and strident whistles. Her subsequent descent to emphasized singular peeps coupled with keyboard rubs neatly wraps up this exciting live set.

Antiworld I's instrumentation may be offbeat, but the session is on the beat creating an in-the-moment session of notable free music.