I'm having trouble getting the approach from Herr Danzer to trigger. I'm arriving in Vienna directly from Paris on day 3 (4am-ish?), and so far I've tried on seeds VI, VII, and VIII with no luck. (Additionally I've tried dining with the composer and the parisian girls, sitting with/without them at the orchestra, skipping the orchestra, admiring the army, staying in the hotel before exploring, etc)

Am I missing an item or manner/valet skill level? 

I can get into Belgrade easily, but it's pointless since I don't have the flute for the achievement.