This eclectic improvising collective led by veteran Dutch free jazz superstar Misha Mengelberg at the piano, known as the Instant Composers Pool, or ICP, has been at their high jinks for over 30 years, with a surprisingly consistent band membership, playing their brand of eclectic improvisation and releasing a hefty catalogue of recording. The current Jubilee Varia is the most recent document of what they've been up to and the impressive range of expressive ideas and timbres they are capable of.

Recorded live in Zurich on two different dates in November 1997, this set captures a stripped down version of the ensemble, which is often much larger. As a nonet, the ICP amounts to a kind of chamber group performing pieces in the band's book. This may seem like a paradox — improvisers performing compositions — but the group works with concepts of modules that trigger improvisations and there is a kind of anarchical conducting that sometimes goes on, with members alternating direction, seemingly at whim. The result is always interesting and unpredictable, except for the quality of the playing, which is stolidly first rate through out.

The first piece of the five-movement suite is a minimalist duo of Mengelberg's playful piano and Han Bennink's puckish drumming. This is followed but what is essentially a string trio, featuring the celli of Ernst Reijseger and Tristan Honsinger alongside Ernst Glerum's double bass in a peaceful, slowly evolving 9-minute piece. This gives way to the more ebullient, quirky extrapolations of reeds and brass, supplied by Michael Moore and Ab Baars for the former and Thomas Heberer's trumpet and Wolter Wierbos's trombone for the latter in a kind of apocalyptic tango... a dance piece buoyed by double bass and drums with the added spice of the leader's spare piano.

The Jubilee Varia suite's two other pieces feature the ICP in full flight in an ironic march-cum-dirge titled "A Bit Nervous Jealous? Me?" wherein the ensemble's ability to respond to the evolving musical textures is on full display. The Varia are closed by the more lyrical, and eclectically textured "Next Subject," and the CD issue of these 1997 concerts is rounded out by a 12-minute romp called "Rollo I" whose in-the-moment aesthetic gives birth to some equally satisfying music.