Yes, you did read that right. The museum stays open until 10pm and tickets are half price from 8pm, so definitely worth a late trip. The museum has a diverse range of exhibits which go from showcasing the Vienna Philharmonic orchestra (which you can conduct, virtually), through focus on different German composers, to the science of music and sound itself. I disagree with previous reviewers who state that you have to love music to go; clearly if you are a musician you will get more out of the museum, but many of the exhibits are fascinating no matter what your level of virtuosity. There are a number of exhibits which are interactive (aside from the conducting), including making a Mozart orchestral piece out of your name, experimenting with different sounds and recording your own piece of devised music.
Go late and if you hate it, you won't have wasted much money; if you like it, you'll feel smug. Like me.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.