Figure 1. Appoggiatura with ordinary and dotted notes.
Figure 2. Appoggiatura with tied notes.
Figure 3. Appoggiatura with a chord.
Sometimes called a leaning note (from the Italian translation), the appoggiatura is an ornament that serves as an unprepared suspension. Important melodically, it suspends the principal note by taking away the time-value of the appoggiatura prefixed to it (generally half the time value of the note, though in triple time, for example, it might receive two thirds of the time). It has a non-chordal note occurring on the beat (accented) and resolves down a step. It is not, however, held over from the previous note, but usually is approached by an upward leap.
1. With ordinary and dotted notes
The appoggiatura is not a timeless 'crushed-in' note like the acciaccatura; it is as important melodically as the note on which it 'leans', from which it takes normally half the time-value, or, if the note on which it leans is dotted, two-thirds of the time-value. See Figure 1.
2. With tied notes
When the appoggiatura 'leans upon' two tied notes, it normally takes the whole of the time-value of the first of these to itself (although see exception noted in the previous section). See Figure 2.
3. With a chord
As the appoggiatura leans upon only one note of the chord the other notes are unaffected. See Figure 3.