Musée Charlier (museum)
I think that if you have a few time in Brussels with MIM, Musée des Instruments de Musique, it is a must as far as museums are concerned. For an extra reason too: even Brussels people don't know it that much. I discovered it by chance in 1997, while wandering in Brussels office district. In fact, this used to be an old art district but offices took over art. The first exhibition I assisted there was "Emile Verhaeren, un musée imaginaire". Focus on Emile Verhaeren, Belgian poet, as a link between Belgian and French artists in 1848- 1914 era. Manet, Seurat, Monet, Toulouse- Lautrec paintings adjoined with Rodin woodcarving pieces, Ensor and Meunier drawings. Visitors could even have a glance at epistolary contents that tied those artistes and "passeurs" (a kind of art smugglers) ... The whole was displayed in a jewel case that is this building that used to be Henri Van Cutsem town house....
