una corda
Italian universal
Definition
One string — depress the soft pedal (left pedal) to shift the action so hammers strike fewer strings, producing a softer, more veiled tone.
Interpretive Guidance
In modern grand pianos, una corda shifts the action so hammers strike two strings instead of three, altering both volume and tone colour. The effect is not merely softer but qualitatively different — more intimate and slightly muffled. Release with tre corde.