I'm hoping to book some concerts for an upcoming trip to vienna and wondered if anyone can recommend a reputable ticket broker. I've gone to www.viennaticket.com and www.mondial.at, but there's a pretty big difference in prices for the tickets. Any suggestions would be greatly appreciated! thanks!

You can go directly to the venue sites and purchase online (depending on what concerts you are wanting to go to). Which concerts are you looking to attend?
Usually you can see what is going on by going to:
http://tinyurl.com/36dvyu
Click on what concert you are intersted in and it will give you a link to purchase. No need for brokers.

Thanks, Operaman. I'm trying to get tickets for the Vienna Boys Choir and can't seem to buy tickets from their website. any suggestions?

Go to:
http://tinyurl.com/3x8tcw
That is the Hoffburg Chapel site and has ordering instructions.

Do you have any suggestions for getting tickets to a concert at Musikverein? Unfortuantely we won't be in Vienna on a sunday and can't attend the choral concert.

Go to:
http://tinyurl.com/2rvmdl
In the top right hand corner click English and go from there.

Oopps, You can also go to the calender of events enter your dates and it will display what is going on while you are there:
http://tinyurl.com/36dvyu
As I said in the first post, you can click the event and it will give you a link to the ticket site.