A ‘dressy’ do I can’t get out of - help!

One of my "top tips " was given to me by a colleague who was a model in the 60s. Get a wide length of silky fabric - habutai is cheap (try Broadwick Silks on-line) or look in Asian fabric stores. For this top, use a plain colour that picks up one of the colours in the top. Wear it slung over one shoulder as you arrive, just draped round your neck when eating or drinking. It gives a top and trousers a "pulled together" look.

It looks mostly navy rather than black - navy palazzo trousers?
Added advantage is you can wear comfy flat shoes!
But I sympathise, my heart sank some years ago when we were expected at an aunts 80th do in Scotland (black tie) it would have involved posh frock for me, DJ for DH and flying up (I was still teaching) plus an overnight stay I was so relieved when we could not find a flight from Bournemouth for DH and had to “regretfully decline”
Weddings are bad enough!

ps - beige trousers, if you can find the right beige would also be fine. Its a very pretty top

How about a knee length (or thereabouts !) black velvet skirt ? Or one of those lovely knife pleated ones.

That top is lovely and I ag with winterwhite trousers or a skirt whichever you feel most comfortable with I was at a wedding last week and all of us of a ' certain age' wore trousers. It was quite a 'posh' do!

Top will look lovely with either trousers or a skirt. If it's black tie perhaps a skirt? And a black bra in case straps show. Have fun!