Orchestra in Vienna - Recommendations

Vienna Symphony Orchestra Dec 20 & 21. Philippe Jordan conducting, Yefim Bronfman doing Tchaikovsky Piano Concerto No 2, followed by Tchaikovsky's Nutcracker Suite. General public sales open Nov 9.
https://www.wienersymphoniker.at/concert/pid/000000e9h58h00021f65

The Stephans Dom (St Stephan's Cathedral) has some Christmas concerts at 8:30 pm (on Sundays, the concerts begin late - at 10:00 pm! ) but the program looks wonderful - totally classical: Mozart, Bach, Haydn, and Schubert. Tickets look expensive ( Eu 46 each) but that's something I would like to do.

Google "Stephansdom Advent Concerts" and see if you get info.

If you just want to hear the usual light classical "hits" (The Four Seasons, Eine Kleine Nachtmusik, The Blue Danube, etc.), there's nothing wrong with the tourist concerts. But if you want something more potentially challenging, go with the Vienna Philharmonic (one of the most prestigious in Europe) or the slightly lower tier Vienna Symphony. But of course, you'll pay far more to hear these ensembles.

The Vienna Philharmonic is something of an "All Star" team that does just a few subscription concerts in Vienna. They do show a Sunday morning (11:00) subscription concert at the Musikverein on the 18th. (Barenboim doing Smetena's Mein Vaterland). Returned tickets and standing room go on sale Dec 12. Otherwise, they will be in Paris and Cologne that week.
https://www.wienerphilharmoniker.at/concerts/concert-detail/event-id/9599

You should try to get tickets for concerts as soon as possible:

https://www.musikverein.at/konzerte/konzerte.php?currMonth=12&currYear=2016
https://www.konzerthaus.at/calendar#month=12&year=2016

Thank you so much for your responses to this! We have booked 2 tickets to the Vienna Symphony Tchaikovsky Piano Concerto No 2, followed by Tchaikovsky's Nutcracker Suite. Any suggestions on dress code for men and women would be very helpful. Should my husband pack a suit and tie? How formal should my dress attire be?

Thank you so much!

Attending a classical concert or an opera: Vienna is not as formal anymore as is happened to be. Although suit and tie would be appropiate for men, a lot of people are more casually dressed. For women an elegant dress is fine, but not a long one, which is worn only when going to a ball.

Pants and a collared shirt or sweater are fine for you both. The venue is the Konzerthaus, which tends to be more casual.