How about this ensemble?

[Domehead]

I think it is well done. My opinion on the application of "Day wear", "Evening wear", Morning wear" are different than others.
I think your "Day wear" is fine because you are attending a concert in which a tuxedo is not required. Effectively you are wearing a nice professor's suit but replacing the slacks with your kilt - and its accoutrements. I like the contrasting waistcoat and jacket. You'll remove your bonnet upon entering. As for the sporran, it is not my place to say because how do I know it is not the sporran you were bequeathed by a late uncle? You may wear this all the time, except for black-tie when you may wear horse-hair. Who knows?

I wear a traditional antler-handled sgian no matter what the level of dress, because it is the sgian my grandmother gave my father, she then gave me prior to her passing. I have never, be it in the States or in Scotland, been asked.

As for your sporran and the "day", "semi", "dress" pickle...
Whenever (no matter the time) I attend any function that requires coat and tie, I wear my custom Wyvern Leather sporran.
Whenever (no matter the time) I attend any function that requires coat and tie, but the function is deemed by third party as "significant", I wear my custom L&M Highland chrome cantle, tartan faced Hunting sporran
Whenever (no matter the time) I attend any function that requires tuxedo I wear my custom Lamont chrome cantle, red fox Full-fur sporran.