Chopin - Nocturne in C-Sharp Minor, Op. 27 No. 1 

Great observation Phillip. 😉 I tend to agree with you. Some of his Nocturnes have similarity to Fantasies Impromptu (especially the one sin C# minor/major).

@@ElenasBarre Yes. I think it all might have to do with certain qualities inherent within a particular harmony, and the possibilities those qualities afford, especially melodically. The F major Nocturne when compared to the F major Ballade is another example. Elena, blessings of the season to you, your family and friends!