Crossing the Thumb "Under"

   In an expression of frustration, my father used to remark that he wished he had a nickel for every time he had to repeat himself. I suppose today, what with inflation and all, it would be more like sixty dollars. I don't mind repeating myself, though, even without getting paid.

    In a public forum a pianist writes: "I've had

trouble crossing my thumb under my third and fourth finger in my left hand when playing scales, causing my hand to stumble and lose its place, for forever." A well-meaning responder offers the following help: "It's the P word [practice?] again. Constant work at the scales starting slow until you're under control and  then increasing the speed will aid muscle memory to the [point] where you will do it without thinking. Like a drill in sports." 

   

Okay. Here's the thing. We don't drill at the piano the way we would in sports, should we be inclined to do sports. The muscles we train at the piano are refined and we work for physical coordination, not for bulk and strength. True, we do repetition training in order to "work in" our technical solutions so that they become automatic. We rely on this in speed.

    And yes we "practice" along the lines outlined in an earlier essay. But in order to move the thumb after we've run out of other fingers, we do not cross it under.  In a descending, left-hand scale (or right-hand), the thumb plays its note and immediately is allowed to hang (yes, hang) behind the second finger. It is allowed (not forced) to move in similar fashion behind each successive finger as that finger plays. This puts the forearm at an angle to the keyboard. (The arm may be at any angle with the keyboard as long as it is straight with itself.) When the thumb is required to play its note, it will already have arrived over it. It then plays by means of a rotation of the forearm, which is our quickest and most natural movement. (By natural I mean that it is a movement the forearm was designed to do.) If instead the thumb is pulled under the hand, the only way it can play is to fall on its note, which produces the result described by the original poster above.

    For a demonstration of this movement, select the tab above labeled "iDemos" and choose "forearm rotation." The discussion of thumb crossings begins at about 4:30. The example is in the right hand; the left is, of course, the same in reverse.   

    Please remember, efficient practicing is deliberate, with the brain engaged. First, decide on the correct movement and only then begin to work it in. Practice on purpose; reject mindless rote.