First it's not New York, so don't expect it to be so. Secondly you're asking for a swanky place in Adams Morgan - college capital of DC, if they actually enforced a dress code there, they would be losing business. Try Georgetown instead. However Felix on the right hand side and Saki seem to be better "lounge" type places with slightly more dressy crowds. Everything else in Adams Morgan is like a free-for-all drink fest, some people dress up, some don't. And it would help to know what kind of music you would like to listen to.