Is it the power of music, or the way that we think about music’s power that most affects us?

Writing in the book Reading Jazz, (Robert Gottlieb, Ed. 1996. London: Bloomsbury), the music critic Gene Lees noted the amazing technique of pianist Bill Evans:

In speaking of the Evans’ technique of playing the piano, Lees wrote, “I kidded him about his rocking finger on a key on a long note at the end of a phrase. After all, the hammer has already left the string: one has no further physical contact with the sound. ‘Don’t you know the piano has no vibrato?’ I said.

“ ‘Yes,’ Bill responded, ‘but trying for it affects what comes before it in the phrase.’ That is more than a little mystical, but he was right.”

Such a view suggests not only the importance of a musical phrase, but how a phrase might be influenced by the player and received by the listener. It is likely impossible that such an “influence” has a physical effect on the sound. Once a bell is rung, it can only sound. Yet, a listener’s expectation of a performer may produce a psychological effect on how the hearer hears, affecting the way the hearer hears the sound, shaping the sound in a way that aligns with the hearer’s expectation. Does the physical sound change? No. Does the effect of the physical sound change the hearer? Yes.

So, is it the power of music, or the way that we think about music’s power that most affects us?