Metropolis Ensemble’s season-opening concert on October 28, Brownstone, won’t fit the definition of a traditional concert. With musicians spread throughout the three-story home of artist Jenny Salomon performing an electro-acoustic composition by Jakub Ciupinski while audience members meander through the house experiencing music, art from the gallery On Stellar Rays, and socializing over a glass of wine, I’m not really sure if “concert” is the right word at all. Installation? Event? Happening? Experience? I stopped by 224 Washington Avenue in Brooklyn to catch a bit of the first rehearsal of Brownstone and to speak with Jenny and Jakub.