New to the forum, have found so much helpful info thanks all! When in Salzburg in December I am planning to dine at Restaurant St. Peter Stiftskulinarium and also see a Mozart concert, noticed they do that as well but had been thinking of the VIP dinner and concert at Fortress Hohensalzburg. I think we can only manage one concert. Grateful to hear experiences and recommendations, thank you!
I advise against the concert at Fortress Hohensalburg unless things have changed since I attended the event in 1996. Though it was a thrill for me, a lover of Mozart, to hear his music performed in his home town, I was a bit disappointed: The musicians were not high quality. It felt like an event staged for tourists only. However, I saw the concert 30 years ago: Perhaps it's changed.
There must be other concerts featuring Mozart in Salzburg, and some of these must feature professional musicians. I'd recommend some research to see what you can find.
It's worth visiting Hohensalburg itself for the views and glimpse of medieval life. The funicular is also fun to ride.
We attended a concert at the fortress in summer of 2023 (a "best of Mozart") and enjoyed it a lot- especially the view from the fortress around golden hour/as the sun was going down. I appreciate you won't have that same experience in December. We ate beforehand at the nearby Stieglkeller which I also quite like.
I recommend seeing if there are tickets available for the concerts at Mirabell Palace during your stay. We went there during our Salzburg stay during the GAS tour last month. The quality of musicianship was excellent and in a gorgeous venue. The tickets were reasonable, but did sell out in advance. We ate at a nearby restaurant beforehand.