Does anyone have a favorite concert hall in Vienna, or a special music venue!
Absolutely , The Musikverein ( home of The Vienna Phiharmonic ) . This spectacular hall served as the model for Charles McKim's Boston Symphony Hall ( which is why it is also terrific ) . When will you be in Vienna , and what are your tastes in music ?
By far, the most famous is the Golden Hall of the Musikverein.
The Vienna State Opera is just fabulous, if you are remotely interested in opera.
You may consult Austria's most comprehensive event directory: https://www.events.at/
It is in German only, but you can easily filter by location (i.e. Wien), date and type (e.g. Musik/Klassik).
If you want to book tickets online, best is to use the website of the respective venue (and not a ticket office).
Another vote for the Großer Saal at the Musikverein. One of the best places on the planet to see a concert