We took the tram and jumped off at the Rathous. I highly recommend walking from here to the Kunshistoriches. The walk is not long, and the views gorgeous.
Before we walked into the Kunshistoriches, we bought tickets to the Royal Wien Orchestra. This was a good concert and very fun. If you have children, take them. The show combined instrumental music, opera, and ballet. Explainations of pieces are done in German and English.
The Kunshistoriches is a fabulous museum. The building itself is a work of art with frescoes and carved designs. The cafe has good food and it not too pricey. We didn't get an audio guide and did fine. Take note of the ways the artists handle different subject matters. We saw Judith, Mars and Venus, and David with Goliath's head several times.