The jazz collection is a very valuable one, with unique compositions and arrangements by sounding names such as Francy Boland, Jean Evans, Elias Gistelinck, Roger Morès, Bob Porter, Sadi, Jack Sels, Toots Thielemans, Jean Warland and many others who were the face of Belgian jazz for many years.

Already in 1936 jazz musician Stan Brenders is allowed to start a big band for the N.I.R.: The Great Jazz Orchestra of Belgium. The orchestra is a great success but the Second World War throws a spanner in the works and because of its waning popularity the big band is disbanded after the war. It would take until the mid-1950s before a new big band was formed under the direction of Francis Bay. When Bay's orchestra was taken over by Etienne Verschueren, it was given a new name: the BRT jazz orchestra. The orchestra embarks on a triumphant tour at home and abroad and during those years becomes a regular at Jazz Middelheim.

A special mention here is appropriate for the works of Polish jazz composers and musicians Jerzy Milian and Jan Ptaszyn Wróblewski in the BOO collection. Both men were active in the BRT jazz orchestra led by Etienne Verschueren in the second half of the 1960s and also wrote several works and arrangements for this orchestra.

The complete opening up and digitisation of this unique collection will take several more years, but it is definitely of great importance for our knowledge of the history of Belgian jazz.