To follow up from my posts at Cimietiere Picpus, both the Carmelites of Compiegne and the poet Andrea Chenier are featured in celebrated operas: Poulenc's Dialogues of the Carmelites, via Bernanos's interpretation of Getrud von le Fort's Song at the Scaffold and Umberto Giordano's Andrea Chenier.
Here is Poulenc's finale at the Met in a classic staging by John Dexter. Note the priest surreptitiously blessing the Carmelites on their way to the guillotine.
At the Opera du Rhin. A less literal interpretation--no crowds, no guillotine!
And the final duet from the Giordano opera--Caballe (!) and Carreras--verismo!! (the Met 1983 Gala--worthy of many more Youtube searches--Freni and Domingo in the great duet from Verdi's Otello; Roberta Peters as Lucia di Lammermoor; Der Rosenkavalier trio with Soderstrom, Battle and Von Stade; McCracken in cowboy boots as Otello--I have it on VHS, not DVD--what a gala!)
And if you like Giordano from an earlier generation: Corelli and Tebaldi--very verismo! The heroine Maddalena meets the poet Chenier awaiting his execution by the Terror. She takes the place of a condemned woman and joins him at the guillotine at dawn. Before that, they have to sing about it--this is opera, after all!