The Belgian jazz orchestra run by BRT radio was one of Europe's most interesting workshops, allowing composers to experiment at will with the sound or structure of works. Jerzy Milian exploited the possibilities of this composition to its absolute limits, and "Optima Fide," the eleventh installment in the "Jerzy Milian Tapes" series, chronicles this turbulent period in his career. Beginning in the mid-1960s, Milian regularly wrote large forms bordering on jazz and avant-garde for Belgian radio. Some of them appeared on the album "Circulations," and "Optima Fide "is a further continuation of this story. The buckle that binds the whole story together here are two expansive compositions written on a grand scale: the 1968 concerto for vibraphone and big band "Realities" and the title suite "Optima Fide", which is two years younger (with a guest appearance by Jan "Ptaszyn" Wroblewski). The album's program also includes atypical compositions, short forms prepared for the Belgians in 1969. "Optima Fide" is the eleventh part of the "Jerzy Milian Tapes" series. All works, originally realized in 1968-70, were remastered from tapes from the artist's archive.