Reddit reviews New England Conservatory of Music Boston, Massachusetts MA Original Vintage Postcard

Great catch! The Conservatory building is tucked away behind the much taller East Village building in most of the shots, so I definitely missed that one! Here's a good shot from a reverse angle which shows some of the same details on the roof of the Conservatory building, such as the chimney, which can be seen in the old map. Here's an old timey postcard depicting the Conservatory Building.

It looks like Building 2, a block up Huntington Avenue, is the Symphony Hall, built a couple of years before the map was drawn, and is still standing today. Building 3 is Horticulture Hall, built just a year before the map was drawn, and survives today as the William Morris Hunt Library.