Hollywood O.K. Pieces (Geestgronden) is technically credited to all involved, but pianist Guus Janssen wrote the music and that gives him an edge in the standings. Janssen has composed an entire opera around the biblical story of Noah, but aside from that he tends to stick to smaller groups like trios and solo settings-including one of the very few (or only?) outings of free improvisational harpsichord on record. On Hollywood, he’s playing live with a sextet, and it’s a terrific one at that. Jannsen’s music has a touch of formality to it, without being staid or stiff. He likes to mix layered themes and free improvisation with echoes of West Coast cool, classic jazz and modern classical, and he couldn’t have picked a better group for this nuanced program. Bassist Ernst Glerum and Guus’ brother Wim, the band’s drummer, give the band deceptively simple support, but the frontline horns, in particular, are irresistible. Peter van Bergen, Vincent Chancey and Michael Rabinovitch play clarinet, French horn and bassoon, respectively-a strange lineup with chameleon powers. They give the music a baroque sound when it calls for it, but they can also deliver the sound of a classic postbop front line only slightly mutated. Van Bergen’s clarinet has some Dolphy and some New Orleans in it, Chancey’s French horn can approximate a trombone and Rabinovitch’s bassoon, which one just needs to hear to believe, can mimic a cello or swing hard as a mystery reed. The band packs this performance with great solos all around, including a thrilling performance by van Bergen at the top of the opening number, “Angelicanzone,” which hits a high the rest of the performance almost but doesn’t quite match.