Appoggiatura
A long, sustained grace note that halves the main note.
What it means
The appoggiatura is the long grace. An auxiliary note steps into the place of the main note and takes up a considerable part of its duration — with a plain note value as a rule the half, with a dotted one frequently two thirds. Only afterward does the main note sound. In German it is also called Vorhalt (suspension) or langer Vorschlag (long grace).
The name comes from appoggiare, “to lean”, and describes the thing well: the grace note leans on the main note and resolves into it. In this a dissonance arises that sounds on the strong beat and resolves on the weak beat — herein lies the effect.
The opposite term is the acciaccatura, the very short grace without a time value of its own.
In the notation
The appoggiatura is notated as a small note without a slashed stem before the main note, usually joined by a small slur. Its written shape says nothing about its actual duration; this follows from rules that differ from era to era. Modern editions frequently suggest the execution in a footnote or above the staff.
Musical use
The long grace is extraordinarily frequent in the music of the Baroque and the Viennese Classicism and belongs to the fixed stock of the melodic language. It is usual especially in cadences and at phrase endings, and in vocal music also where it is not notated — performance practice expected it at certain places. In the music of the nineteenth century it is increasingly written out.
The name stems from appoggiare, to lean. It is played on the beat.
Performance practice
Give the grace note its full duration and emphasise it, not the main note — the resolution is the lighter part. Play the grace on the beat, not before it. Let the loudness yield toward the main note, so that the resolution becomes audible as such. And with older music check what duration the edition suggests before you commit yourself.