outift advice

[MacMillan of Rathdown]

I note, as an aside, that several individuals have suggested "wear what you want".

As someone who enjoys a "grace and favour" flat in Vienna (on Goethegasse, inside the Ring, and about 200 meters from the Opera) I would respectfully suggest that the standards of formal dress in Vienna are different (ie: higher) than in the USA.

That said, when attending balls in Vienna I always adhere to the dress as stipulated on the invitation. White Tie means just that-- white tie and tails. Black Tie means a dinner jacket. Unless the invitation specifically states "Highland Attire" I don't wear a kilt. (In 35 years I have never received an invitation to a ball in Austria that said "White Tie, Highland Attire".)

As far as going to the opera is concerned... opening night is always black tie, as is the last night. In between it's a dark suit.

Personally, I would no more wear Highland attire to a ball in Vienna than I would wear lederhosen and trachen to a ball in Oban.

Even if I was advised to "wear what you want", I just wouldn't do it.

[Zardoz]

Joeydknecht,
Since you are talking about a U.N. event, you more than likely will see people there in various ethnic attire. The invites for UN Association Balls I've attended in the past said 'Black-tie or national costume' if I recall.
I would wear your tartan though, the all black look is either too Hollywood, or too conformist not sure which! I also see you mentioned a belt buckle along with the PC and waistcoat? As is often discussed here, one generally doesn't wear them both. Have fun!