Genealogy information is wherever you find it! One unusual resource is a database of subscribers to the New York Philharmonic up to about 1953. It is indexed and linked to digital images of the subscription books. The books contain names and home address of concert goers. This may be a great resource for someone with ancestors in New York City.
You can access the list of New York Philharmonic Subscribers, 1883-1907 at: http://archives.nyphil.org/index.php/subscribers.
My thanks to newsletter reader Mike Provard for telling me about this online resource.