Brussels organized, among others, Jazz à tous les étages (or Jazz on every Floor). It consisted of a short concert played by 15 or so musicians, on Place de la Monnaie in the center of Brussels. Then, they walked to Grand Place, still playing.

Part of the musicians left the band, to appear at the windows in the street, where they continued to play.

It ended with another short concert on Grand Place.

More photos can be found here. And a small video is here.