Shortly after the museum was founded in 1877, the collection was laid up in an annex of the Royal Conservatory of Music in rue aux Laines/Wolstraat. The Conservatory moved into a new building designed by architect Jean-Pierre Cluysenaar on rue de la Régence/Regentschapsstraat.

The museum also acquired a large town house on the corner with pl. du Petit Sablon/Kleine Zavel, which became the home of director François-Auguste Gevaert (1828-1908). But the collection grew so quickly that it soon proved necessary to find new premises.

Moreover, the conditions in which the instruments were stored had to be improved. The situation became so critical that in 1926 Louis Cavens threatened to reclaim the items he had gifted to the museum if the government did not take appropriate action. Though there were promises, in reality they amounted to no more than temporary solutions. The store in rue aux Laines/Wolstraat was enlarged and the beautiful building on the corner with the Sablon/Zavel was converted into an exhibition space.

gravure de 1898
engraving from 1898
prise de vue en 1976
the facade in 1976
prise de vue en 2000
the mim in 2000

Not until the end of the 1970s - by which time the collection was spread over no fewer than fifteen buildings in the Sablon and Nord/Noord areas - did the federal government wake up to the fact that a total solution had to be found for the mim. Eventually in 1978 the former Old England buildings were purchased to house not only the exhibition rooms but also the reserves and the administration.  

These two buildings were very different in style. The neoclassical building on the pl. Royale/Koningsplein was part of the design for the whole square laid out in 1774 under the direction of architect Barnabé Guimard. It was inspired by the place Stanislas in Nancy.

The building on the Montagne de la Cour/Hofberg is one of Brussels' art-nouveau gems. It was built in 1899 to a design by architect Paul Saintenoy. Moreover, a third, new building was erected on the rue-Villa Hermosa-straat for storing items not on show.

All this work took several years to complete. In December 1998 the mim officially took possession of the keys to the buildings. The collection was transferred there in the course of 1999. The move took ten months. The new mim opened in June 2000.