Dear Mr. Chappell:
I read your wonderful article about Schnabel and Fleisher (http://jeffreychappell.com/kb_schnabel.php ). When you talk about the “shape” of the phrase, what do you mean? I know that is a very important concept in Schnabel’s teaching. When one should think in phrases, should one think in triangles, circles? it just doesn’t make sense to me.
I like your question, and I especially enjoyed the part about triangles and circles. I can understand your bewilderment.
A phrase is a group of notes. The group has a first note and a last note. For one thing, a phrase has shape because it has length.
That seems simple, except that different interpreters will group the same notes in different ways by beginning and ending in different places, or by subdividing a long phrase into shorter groups of notes.
For example, measures 3 and 4 of the Bach C Major Two-Part Invention are a steady stream of sixteenth notes. How many possible ways can you group these notes into subdivisions of four, or eight, or some other number, starting and ending on different notes? Many.
Between the first and last notes of a phrase, there is a point that has the greatest concentration of energy. All notes either go to, be there, or come from the point of concentration. For another thing, a phrase has shape because it gathers and disperses energy around this point.
For example, at the beginning of the Brahms Intermezzo in A Major, Opus 118 Number 2, there are two upbeat eighth notes before beat number 1 (going to), then there is the note on beat number 1 (being there) followed by some eighth notes in the left hand (coming from).
A phrase also has shape because of fluctuations in dynamics and tempo.
In the case of using dynamics, it would be natural to get louder when approaching the main energy point of a phrase, and to get softer when departing from it. It also can work to make a diminuendo to approach the most important note of a phrase to highlight its importance.
In the case of using tempo, it would be natural to speed up when approaching the main energy point of a phrase and to slow down after passing its main energy point. It can also work to slow down when approaching the main energy point to highlight its importance.
A phrase can be shaped using fluctuations of only dynamics without fluctuations of tempo, and a phrase can be shaped using fluctuations of only tempo only without fluctuations of dynamics.
Different interpreters will make different choices. Where one person makes a crescendo and accelerando to a particular note, another might do the opposite, or even choose a different note as the main point of the phrase. It all depends on the style of the music and on the interpreter’s musical taste.
Finally, at the piano, as mentioned in the article you asked about, the pianist’s arms, wrists, and hands can make gestures that “trace the shape of each phrase, as if choreographing the music.” These gestures move in shapes that are not triangles, that are sometimes circles, but mostly that are curved lines.
They are like the gestures an orchestra conductor makes except that the fingers are held in contact with the keyboard. It is a way of living out the continuity of the sound after putting down the key on the piano, and it keeps the pianist psychologically engaged with the music.
When the playing is slower and is produced more by the arm, as in the languid melody of a Chopin Nocturne, the music is more suited to this choreography. When the playing is faster and is produced more by the fingers, as in a Chopin Etude, the music is less suited to this choreography.
I invite you to leave further questions and comments here so that I can clarify this more if necessary.