Trying to decide where to go

Considering the things all of you would like to do, the answer is Austria. Close to Germany for your brother, and there are performances by the horses in Vienna. The scenery is beautiful all over the country, and there is a wealth of music, museums, and history. In addition to Vienna, there is Salzburg and Innsbruck. Do a bit of research on those three cities and see how they fit your needs.

I agree with TC. Vienna cannot be beat for music and museums, and the Lippizaners will make everyone happy. You might want to consult the schedule of the Staatsoper, Volksoper, and Musikverein as you choose your dates. The setting in the foothills of the Alps complete with vineyards is very charming as well. It is also close enough to the Wachau to see castles and sample wine on a boat ride from Melk back to Vienna. The Imperial Treasury with the crowns of the Holy Roman Empire and the Austrian/Hungarian empire will satisfy any history buff. Salzburg and Innsbruck will give you access to great alpine scenery plus their own charm and history, just the train ride between the two is wonderful.

I have to agree about Austria based on the interests you listed. It checks all those boxes except the beach. With two weeks you could spend some time in Bavaria and/or Hungary. Munich, Salzburg, Vienna, and Budapest would be good bases and you wouldn't spend too much time moving between them. You might find a boat ride on the Danube to see the Wachau Valley and other sights. It makes more sense, given what you want to see and do, than trying to spread across three countries on opposite ends of Europe in just two weeks.

Look at some guidebooks and see if you can come up with a list of places you want to visit in that area. Maybe a rural setting for some of your nights if you want to be in the countryside -- but keep in mind that public transportation doesn't work as well as a car for rural areas.

I agree that based on your interests, Vienna is a good fit. I might toss it out there to stretch a bit and fly into Budapest and out of Munich or Vienna. Budapest is an amazing place for music - and has some interesting museums. 5 nights would not be too many.

Then it would be an easy train trip on to Vienna - more good music and museums, as well as the Spanish Riding School there. Because you would not be arriving with jet lag, 4 nights might be enough for me.

Then you could easily head on down the train track to both Salzburg and Munich (or stop with Salzburg and take day trips out into the beautiful nearby nature). Depending on where you decide upon, fly out of Vienna or Munich - although last year, I found tickets equally cheap out of Salzburg, so you never know.

Is there a reason why you want to visit one country / place only?

In the given three Austria with mountain countryside and its cultural background is a real good candidate but also France with unique and European top 3 site Louvre. The French countryside is imo the most manifold and offers everything from rough Atlantic coast over mountains (comparable to Austria) to warm Mediterranean.

From what you describe also Germany and Berlin can be an (additional) option. Berlin from the range of culture (over 170 museums) and history but most of classical music. We have three large opera houses plus further orchestral places. Unique is at Pentecost the annual Festival of Cultures. The area around Berlin becomes very quickly countryside like - Harz mountains are beutiful and offers places like Goslar. Price level is significantly lower than Vienna and Paris.

If you prebook early enough transport is not so expensive. There are also night trains (NightJet) between Vienna and either Paris or Berlin and also between Paris and Berlin.

Good luck and please post after journey what your decision was and how you liked it.

Thank you! Very helpful advice so far. Sounding like Austria might be the winner, which makes me happy, as that is my top choice personally. I just want to make sure my dad will be happy (I’m young and hopefully will travel to Europe many more times, but this may be his only chance, given his health). I am intrigued by the possibility of seeing both Vienna and Paris, though. I guess we hadn’t really considered how easy it might be to travel between bigger cities in Europe, and we were worried about trying to fit too much in and feeling overwhelmed. But looking online it seems that flights between those two cities are very fast and cheap. How does 3-4 days in Vienna and 5-6 in Paris sound, with a day to navigate traveling between them and 2-3 days in a smaller city or countryside somewhere nearby (alps perhaps if we fly into Munich)?

Just pick the top three things you have to see, and plan around that.

Every city will have museums. Unless there's one you MUST see, plan those after you get a location down.

Likewise music. It's everywhere. There are hundreds of music festivals every summer, and every town and city will have local stuff that you'll only find out about by reading the posters on the walls or kiosks. I've experienced concerts in the park, classical combos in the cathedrals, and even an hour long organ concert in one church all by coincidence in the last 3 months. Cities with music schools, like Munich, Prague, or Salzburg, will always have players in the streets come evening.

France, outside of Paris (especially this year) is not expensive. Bigger cities usually cost more than small towns, tourist places are priced accordingly, and prices do vary with the time of year. May is the beginning of tourist season, but a really good time to visit.

So, my "go to" recommendation for two weeks in the EU, for someone who's never been here, is Munich, Prague, Salzburg. This can be tweeked, but IMHO it offer you castles, history, architecture, scenery, great food, world class museums, music, great accommodations, and all three cities are within reach of dozens of other places you can get to by public transport with no trouble.

Yes, there are a lot of other fantastic places to visit, but those three are an excellent combination of attractions, they are easy to get to without wasting precious time moving from place to place, and they are easy to explore.

...3-4 days in Vienna and 5-6 in Paris...2-3 days in a smaller city or countryside...

Five days in Vienna will give you one day for a day trip to somewhere nearby. Perhaps the brother can see his friend in Germany? Six days in Paris will give you time for a day trip or two. Perhaps Reims or Versailles. That leaves three to four days for another location to be decided by the group.

So many are voting for Austria but it doesn't have any beaches. I vote for France.
Start in Paris (food and museums), make your way to Strasbourg (meet German friend), then down through Lyon towards Nice, hitting the Alsace (wine) and L'Occitane regions along the way. Take a day-trip from Nice to Eze, Monaco, Menton, or Grasse, the perfume capital. Continue east along the Riviera (beaches) to Toulon and head north to the Loire Valley (castles), then back to Paris.

Thanks everyone for all the helpful tips and ideas! We clearly have quite a bit to discuss and research as a group.