appoggiatura explained
An ornamental note that falls on the beat, creating a dissonance that resolves by step to the main note
In Depth
The appoggiatura (from the Italian appoggiare, to lean) is approached by leap and resolved by step, leaning into the main note with expressive weight. In Baroque music, appoggiaturas were often written as small grace notes but performed on the beat, taking half or more of the main note's value. This performance practice is crucial: playing the appoggiatura before the beat (as a modern grace note) fundamentally changes the musical meaning. The appoggiatura is one of the most expressive ornaments in Western music.
The second movement of Mozart's Piano Concerto No. 21 is filled with appoggiaturas that, performed correctly, create an almost unbearable tenderness.