Things you NEED to do in Vienna.
I don't think I've been dissapointed by ANY performances here in Vienna so far. As a music major, my goal was to see as many performances/concerts as I can see throughout the semester. There are three major performaning halls : Staatsoper, where most of the opers and ballet are held, Musikverien, where the Vienna Philharmonic usually performs, and the Konzerthaus, mostly chamber music and pop concerts as well, and even Vienna Phil as well.