129. The words una corda (lit.—one string) indicate that the "soft pedal" (the one at the left) is to be depressed, while the words tre corde (lit. three strings) or tutte le corde (all the strings) show that the same pedal is to be released. These expressions refer to the fact that on grand pianos the "soft pedal" when depressed moves the hammers to one side so that instead of striking three strings they strike only two (in the older pianos only one, hence una corda), all three strings (tre corde) being struck again after the release of the pedal.
130. Other terms relating either directly or indirectly to the subject of dynamics are:
Con alcuna licenza—with some degree of license.
Con amore—with tenderness.
Con bravura—with boldness.
Con celerita—with rapidity.
Con delicato—with delicacy.
Con energico—with energy.
Con espressione—with expression.
Con forza—with force.