Jef Gilson (born Jean-François Quiévreux, 1926) had played clarinet with Claude Luter in Boris Vian's band, switched to piano in 1947, and in 1963 formed the big band through which half of French modern jazz would pass. In 1965 he was musical director of Les Double Six. That year Woody Shaw and Nathan Davis played in his orchestra. New Call From France, released by SABA in 1966 and credited to the Jef Gilson Nonet with Jean-Louis Chautemps, is the record he made for the Black Forest label at the height of that activity.
Wikipedia's account of his writing describes compositions in which harmonic function had been overridden since 1964 without being exclusively free: tempo changes, bitonal layers, chromatic themes. Chautemps, the tenor player who would later be in Gilson's Malagasy projects, is the featured soloist. Dusty Groove calls the original so rare you will never find it, and describes Gilson as a fiercely modernist French player of the 1960s.
Gilson went on to found the label PALM in the 1970s and record the Byard Lancaster sessions that Souffle Continu has just boxed. This is the earlier Gilson, the arranger, before Madagascar.
Japanese CD edition from Solid's MPS series.