Acciaccatura Definition

An ornament note that is one half step or one whole step higher or lower than a principal note and is sounded at the same time as the principal note, adding dissonance to a harmony.

In keyboard music of the Baroque period, a short grace note sounded together with the principal note or chord, but quickly released.

(music) A short grace note (theoretically taking no time at all), occurring on the beat occupied by the main note to which it is prefixed, one scale-step higher or lower than that main note. (Sometimes equivalent, therefore, to a short appoggiatura, but in Baroque music interpreted differently and more strictly.) Written as a note lighter in appearance, typically a quaver (eighth note), with an oblique stroke through the stem.