The questions of rhythm and dynamics play an important role in any system of musical interpretation.

Most pianists in the epoch in question built their playing on rhythmic and dynamic “waves,” made into a principle by Leschetitzky. Busoni rejects this principle. He classifies constant rubatos, “coquettish” “long established” quickenings and retards, “well-rounded” ritardandos and accelerandos, “surging” beginnings and “melting” ends as bad taste. Himself playing, according to the critics, “extremely metrically,” he demands of others—especially in Bach—“consistent motion,” “strictly rhythmical playing,” distinct articulation of every eighth note, conjunct, nonarpeggiated chords: “it is especially important to make sure that all the notes of the chord sound strictly simultaneously.” His favorite comments include molto misurato, senza espressione, ni licenza alcuna; recht schnell, doch geschwind; mässig bewegt und klar phrasirt; mässig geschwind, mit rhytmischem Accent; ruhig, ruhig bewegt, in gleichmässiger Bewegung, egualmente, misuratamente, ritmicamente, articolato, marcato, ben in tempo, mit festem Rhytmus, mit praecisem Anschlag, zusammen, non arpeggiato, non accelerando (nicht eilen!), non rallentando (nicht schleppen!). Busoni's propensity for even, clear, well-defined rhythmic character compels him to translate Bach's cadenzas, trills and fermatas strictly metrically, and, in places, to change the layout, to bring it into a sharper metrical “relief,” to emphasize a metallic sharpness, or an even stream of pizzicati (as in the ninth Variation of the A-Minor Etude of Paganini-Liszt).