Romance, from 4th symphony op.32

Surely not the best known neither most played from Vierne's pieces, but IMHO at least equal to the better known "Clair de lune" from op.53.
It is a kind of very singing Nocturne (in d flat, the typical tonality for nocturnes), with a cello-like theme. The sky becomes suddenly darker and threatening in the agitated central part ; the calm comes back for the peaceful last part (flute harmonique and voix céleste).