I will be spending a week in Vienna and Salzburg exploring these cities
for the first time.  I have my concert program almost set, and I have
an idea which general tourist sights are of interest to me.  However,
I haven't been able to find a good source of information on the sights
with musical connections, e.g.  houses where composers lived, famous
gathering places, places where famous concerts took place (e.g.  patron
residences) and other such sights in these irrevocably musical cities.
I am aware of the Beethoven houses in Vienna, and the Mozart house in
Salzburg, but what about Schubert, Bruckner, Brahms, Mahler, etc.?  I
suspect there have been books written on the subject, but I haven't found
any yet.  Suggestions?

Thanks for your help,
Igor