The attached files capture the varying duration of beats (measured in seconds) in Sergei Prokofiev's recorded performance of his own Diabolic Suggestions, taken from his Four Pieces for Piano, Op. 4.
PLEASE NOTE: In this analysis, Prokofiev’s time signature of 2/2 is ignored. Beats as described in this file are defined as crotchets in relation to Prokofiev's score - essentially they are treated as if Prokofiev writes 4/4. Bar numbers are included to clarify this.