If I play a string of notes where the numbers of the fingers playing them go up (e.g, finger numbers 1-2-3-4-5) or down (e.g., 5-4-3-2-1) then I cannot alternate supinations with pronations in as straightforward a way. (I could, but it would feel awkward and wouldn’t result in rebound-enhancing landings.) In Taubman, you get your fingers back up in these situations, after landing dead on the key, either with a string of pronations or a string of supinations. These are “double rotations”—“double” because each note needs its own “prep swing,” creating a “double motion” by the time your finger has descended into the key. (Knowledgeable people understand that the first two fingers to play in three-, four, or five-finger run would be connected in a single rotation. Newbies, don’t worry because this detail will become clear shortly.)
Sit down at a table again and see if you can observe which direction of forearm preparation is best when finger numbers are ascending, and which is best for finger numbers going down; the Taubman-consistent answer is coming up later in the article.
Double rotation is used where a note needs its own preparatory swing. Singles are preferred in the technique, but the double is used wherever single rotations are for some reason undesirable.
Both kinds of rotation provide a means of getting fingers up and prepared for striking a key or keys that is an alternative to lifting fingers individually, so that we needn’t ever curse, quaintly or otherwise, about agonizingly overtaxed finger muscles again. In single rotation, each downward movement into a key engenders the next needed prep swing in the opposite side of the forearm, and depends on a see-saw movement in the forearm. In double rotation, the pianist prepares for each individual note using either a supination or a pronation of the forearm. This “prep” can be likened to the upward swing the golfer uses before striking the ball.