The top two photos on the left are of the building at 42 rue Notre Dame Lorette - the location of the great organ builder Aristide Cavaillé Coll's first organ factory. (Here is a list of locations and specs of Cavaillé Coll organs): (also see)

The next two photos are of the Paris home on the Rue de Rome of French poet Stéphane Mallarmé (English version) hosted his famous Tuesday soirées where composers, musicians, artists and writers met. Then we have photos of Claude Debussy's home at 10 rue Gustave-Dore and on the right at 58 rue Cardinet, where Debussy wrote his opera Pelléas et Mélisande (English).

The final three photos were taken of the home of the composer Ernest Chausson located at 22 Blvd de Courcelles: