A grace note is a music symbol that represents a small, quick, and ornamental note that is played just before the main musical note. It is often used to add a touch of embellishment or expression to a melody. Other synonyms for the grace note include appoggiatura, acciaccatura, and crushed note. Appoggiatura is a type of grace note that is played as a quick note before the main note, but held for longer than an acciaccatura. Acciaccatura is a grace note that is played quickly and abruptly before the main note, and it is often used to create a rhythmic effect. A crushed note, on the other hand, is a grace note that is played quickly and forcefully, often producing a dissonant sound.