Is the polonaise Nr1 Opus 40 the easiest piece of music of the all Chopin's Polonaises?
I would say that it is probably the easiest of the polonaises
and its repetition makes it easier to learn. It is the one I
learned first but it is by no means easy to play well. The first
four polonaises, being opus 26 no. 1 and 2 and opus 40 no. 1 and 2,
do not contain any severe technical hurdles and should be
manageable by a post grade 8 pianist. All the others are impossible
to anyone but the most talented of piano players.