>>2828044
>Lurking for the best way to spend a day or two in Vienna since it's that's where I'm arriving in Europe soon.
OP has issues with ordinary travel goals, food, history, art and architecture. But in general, Vienna was leveled in the war, so expect a lot of rebuilt concrete buildings, of course. The city is pretty however.
Cafe culture is major, so do hit up whichever cafe had your favorite visitors from old generals, to poets or artists. Get your schnitzel, and famous cakes like Sachertorte, and pastries as well as coffee. I like Cafe Sperl.
There are many daytrips for biking, taking a commuter train, or cruising down the Danube river. You can go down to Melk, the largest intact old library, at that Monastery. Cruise on an open deck ferry boat, one way to leisurely watch the bikers, (often naked) sunbathers and little towns along the way like Durnstein and Krems. You'll pass the ruins of castles and go through wine-growing valleys.
Within Vienna, you can tour the Sisi Palace, visit many art galleries, try specialties at farmer's markets. There are indeed many ways to hear strings and music, not the least of which is just to visit a cathedral or two.