To commence then with the study of passages in thirds: A great many people seek to play these in what I term a “player-pianistic style” instead of a “pianistically plastic” one. By this I mean that they make a point of striking both the notes that compose thirds together with exactly the same pressure of tone, thus giving no doubt an absolutely mechanical precision to double note progressions, but thereby taking away from them, in my opinion, all their melodic character and charm. For I maintain that all passage playing, whether it be in thirds, sixths, or single notes, should necessarily preserve a melodic outline,”I otherwise it degenerates into mere sequences of notes for the display of agility and loses every musical significance.
For whereas some regard elaborate passages as entirely mechanical embellishments, the earnest musician will realize that this is not often the case; on the contrary, close analysis will almost always prove them to be intricate and reasoned embroideries of melody.
Now in single note passages it is easy to obtain some sort of musical contour, because the brain has only one line to develop. But with double notes this is all far more complicated, especially as the melodic ideal remains to be achieved here, just as much as in the simpler case. And hard enough as it is to accomplish satisfactory results with only one finger to think of, what is to be done when two are having to be managed at once?