On a grand piano the soft pedal shifts the whole action, including the keyboard, slightly
to the right. The result of this is that hammers that normally strike all three of the strings
for a note strike only two of them. This softens the note and modifies its tone quality but
does not change the touch or feel of the action. The soft pedal was invented by Cristofori
and thus it appeared on the very earliest pianos.
In the eighteenth and early nineteenth centuries the soft pedal was more effective than it
is today, because pianos were made with only two strings per note and therefore just one
string would be struck. This is the origin of the name ‘una corda’ which is Italian for
‘one string’. In modern pianos there are three strings per note, except for lower notes
which have two and the very lowest which have only one. The strings are spaced too
closely to permit a true ‘una corda’ effect because if shifted far enough to strike just one
string on a note at a time the hammers would hit the string of the next note.
On an upright piano the soft pedal works entirely differently. It operates a mechanism
that moves the resting position of the hammers closer to the strings. Since the hammers
have less distance to travel this reduces the speed at which they hit the strings and hence
the tone volume is somewhat reduced. This, however, does not change the tone quality in
the way that the una corda pedal does on a grand piano.
The sostenuto pedal, or middle pedal, is found on grand pianos. It keeps raised any
damper that was already raised at the moment the pedal was pressed. This makes it
possible to sustain individual note(s) while the player’s hands are free to play other notes.
This is useful for pedal points such as are found in organ transcriptions.
Some upright pianos have a celeste pedal which can be locked into place by pressing it
and pushing it to one side. This drops a strip of felt between the hammers and the strings
so that the notes are greatly muted.
PERFORMING PRACTICE
Performing practice of pianists born in the nineteenth century, especially those born
before 1880, included the use of the following nine interpretative devices:
! Melody delaying: playing the right hand melody slightly after the left hand
accompaniment;! Melody anticipation: playing the right hand melody slightly before the left hand
accompaniment;! Arpeggiata: arpeggiation, rolling, breaking, spreading of chords where not so
marked by the composer, for reasons other than the limitations of an insufficiently
large hand;! Chopin rubato: hastening and then lingering within a phrase;