Early in the twentieth century studies on perceptual‐motor tasks concluded that rhythmic processes generate harmonic characteristics in performance measures. Later this conclusion was discarded in favour of opposing theories. A statistical technique for use in obtaining new evidence for a theory of harmonic characteristics is outlined. Studies using this technique have obtained statistically significant evidence for the existence of harmonic characteristics of performance measures within the range 0.2–60.0 min. A brief outline in support of this conclusion is given and its relevance is discussed for investigations of perceptual‐motor performance.