A student of Rachmaninoff, Ruth Slenczynska, recalled:

I remember how Rachmaninoff explained to me the problem of phrasing: he showed me an elastic band and stretched it slightly, then allowed it to bounce back; next, he stretched it beyond a certain point, and it snapped. He meant to say that no part of a musical line should be stretched out of proportion to the whole composition. We have a natural tendency to take a breath, so to speak, after each phrase, but we must be careful not to overdo it. Actually the end of one phrase should prepare the listener for the next, or at least blend into it so that the musical fabric remains strong and whole. There are even instances in which a whole series of phrases leads to a sort of gateway opening up a new mood, almost as if another light had been turned on—for example, the E-flat chord in bar 21 of the second movement of Chopin’s F-minor Concerto.

R. Slenczynska, PianoMusic at your fingertips; aspects of pianoforte technique, advice for the artist and amateur on playing the piano, New York, Da Capo Press, 1974, p. 20.