In places like Vienna and Budapest , appropriate attire in Opera and concert venues is an integral part of the culture and it is generally expected that audience members will show respect by dressing in the proper way . Many Americans ( not all ) have a well deserved reputation for , to be blunt , dressing like slobs . Here in NYC , when attending a performance at the Metropolitan Opera , I am appalled to see a substantial portion of the audience dressed in jeans and white sneakers . Having said that , One need not pack along white tie for a performance . For me , packing light on an extended trip is necessary . You don't need to go overboard , but for men a nice pair of dress slacks . a dress shirt and tie , does the trick . My wfe wears a female counterpart , perhaps with a nice scarf or some other appropriate accent . Also , when it comes to shoes , I wear one pair on my trip , but they are of dark shade so that they don't attract attention . I don't think you would be refused admittance to a performance if you wore jeans , but you can abide by the accepted expectations without going overboard . In any event enjoy "Swan Lake " , I'm envious !!