How to get a sold out Classical concert tickets? (Vienna)

Hi Guys,

I do seek your help and would be very grateful for any advice on this subject.

I am a big classical music fan -especially late Romantic period and Opera- and always having trouble getting a ticket in Vienna for popular concerts.

Most popular concerts seem sold out during subscribed members only period and some are even sold out 10months before actual performance date.

I live in Korea and electronic ticketing system is quite good here, I can always scout for cancelled one on the mobile application as there's always someone canceling tickets and it will be reflected on the system almost instantly.

Is there such a system in Vienna? Mobile handphone application, or online buy/sell ticket community for cancellation? How does Viennese cancel a ticket when they cannot make it ?

I know each concert house does arrange resell of returned tickets few days before actual concerts but as I have to plan in advance flying from a different continent, I cannot rely on such pure luck going all the way to Vienna without holding a ticket.

I would really appreciate if anyone could share some information on this ...