Agatha Christie Question

Cafe Society
1

When in doubt, I turn to you. I have read all of Christie several times over the past few decades, but I cannot identify this one mystery I keep thinking about. Please help.

I know it was a book and not a TV episode or movie.
It involved an English village, but I am almost 99% sure it was a Poirot novel, not a Marple one.
The main characters in the book were putting on a play–I want to say a play entitled something like O Susannah or Susanna.
The local McBossyBoots bought the farm an ingenuous way: she was shot as she sat at the piano. The piano killed her. The gun was rigged up to go off at some point during her playing and covered by the fabric inset that old upright pianos used to have.

IMS, there was a pair of star-crossed lovers, too.

I cannot recall the title of this book. It is driving me slowly insane.

Can anyone help? I looked through Novelist last night, but couldn’t find the appropriate search terms. Using google just gets me all of Christie’s work.

Thank you in advance.

2

Overture to Death by Ngaio Marsh.

3

Thanks - that saved me from going through all my Christies, because I remembered that plot too and the Marshes are in a different bookcase.

4

OMG. So not Christie at all. Well… that would explain that! Thank you! Now I can check it out from the Library once again.

I’m probably still going crazy slowly, though.