What are the current hours to catch the organ concert at St. Sulpice. What times on Saturday night or Sunday afternoon?
I'm not seeing any regular organ concerts this fall.
Organ music on Sundays before and after the 1100 mass., and during the Sunday masses.
https://www.paroissesaintsulpice.paris/la-musique-et-les-orgues/
There is one concert in October and one in December:
https://www.classictic.com/en/paris/eglise_saint-sulpice/617/?fin=c8&r=1415275
St. Eustache has organ concerts many Sunday afternoons. (Or at least they did in the before times.)
There is a 30-minute recital every Sunday at noon.