Which term is used to describe music that is played softly?

The term that describes music played softly is "piano." In musical terminology, "piano" indicates a dynamic level where the music should be performed quietly. This term is derived from the Italian word for 'soft,' and it is a fundamental dynamic mark that musicians use to guide the volume of their performance.

In contrast, mezzo forte refers to a medium loud volume, and legato indicates a style of playing that is smooth and connected rather than a dynamic marking. Largo describes a slow tempo rather than a volume level. Understanding these terms helps musicians interpret written music accurately, ensuring the intended emotional effect is conveyed through dynamics and expression.