The soft pedal or una corda pedal is placed leftmost in the row of pedals. In grand pianos it shifts the entire action/keyboard assembly to the right (a very few instruments have shifted left) so that the hammers hit two of the three strings for each note. In the earliest pianos whose unisons were bichords rather than trichords, the action shifted so that hammers hit a single string, hence the name una corda, or 'one string'. The effect is to soften the note as well as change the tone. In upright pianos, depressing the pedal moves the hammers closer to the strings, allowing the hammers to strike with less force. This produces a slightly softer sound but no change in timbre.
the soft pedal or una corda pedal is placed leftmost in the row of pedals in grand pianos it shifts the entire action/keyboard assembly to the right (a very few instruments have shifted left) so that the hammers hit two of the three strings for each note in the earliest pianos whose unisons were bichords rather than trichords the action shifted so that hammers hit a single string hence the name una corda or 'one string' the effect is to soften the note as well as change the tone in upright pianos depressing the pedal moves the hammers closer to the strings allowing the hammers to strike with less force this produces a slightly softer sound but no change in timbre