Campbell replies: Although I don’t recognize the musical context Jon Orloff refers to, he raises several interest- ing points about “harmonics” in piano music. The term is used to describe a common technique in violin and guitar playing in which the player touches the string lightly at a distance L/n from the bridge, where L is the string length and n an integer. The light touch suppresses the modes of vibration of the string when it is sounded, except for modes that have a node at the point touched.
To obtain this effect on the piano, the player reaches inside the instrument with one hand to touch the string while playing the keyboard with the other. I don’t think the technique was used at the time when Camille Saint-Saëns was composing. A more likely explanation has been suggested by Anders Askenfelt, the piano acoustics expert at KTH in Stockholm. A carefully judged and forceful accent on the relevant note gives a sound rich in upper “harmonics.” Depressing the sustaining pedal just before the note is struck allows sympathetic vibrations from unstruck strings to contribute to the mix of high- frequency components, which are, in fact, slightly inharmonic. The high- frequency components decay faster than the lower frequencies, and the resulting sound has some similarity to that of a struck bell.
