To understand how suspended notes work, first, we need to know what produces these harmonic and melodic movements in music. Music is a language, but although it has many similarities with the spoken language, music is a “Gravitational Language.” The Harmonic and Melodic movements in tonal music are governed by the “Law of Gravity” that is why we have the so-called “Tonal Centers.”
Melodic and harmonic resolutions happen around these tonal centers. The tonal centers are the notes or chords with the stronger centers of gravity, compared to all the other notes or chords within the tonality, just like the Sun, Jupiter and Saturn have stronger centers of gravity than all the other planets in our solar system. In the case of the musical notes, there are notes that have a greater center of gravity than others.
The notes with stronger gravity centers are the notes of the chord, the tonic or root of the chord is the strongest of all. When we are in the root position, it is said that we are in a state of complete stability. The melodic and harmonic movements are produced when we move away from this tonal centers. As soon as we move away from these tonal centers, gravity starts pulling the notes back down toward the center (root or tonic).
For example, if we are on the chord of Am the notes of the Am chord are A (Root), C (minor 3rd), E (Perfect 5th). A is the root or tonic, and it has. Therefore, the strongest center of gravity and all the other notes are pulled back to it. The notes will be pulled down to the closest center of gravity.
On the scale of C major, if we play the chord of C. C, E, G will be the notes with the strongest center of gravity and all the other notes of the scale (D, F, and B) will tend to move or resolve to the closest strong center of gravity. Understanding this concept, now we can say that a suspension is a delay of a harmonic or melodic resolution. When we stop on a note that is not a note of the chord a “suspension” is created, and that suspension will eventually need to be resolved. (please watch the video to see music examples of this concept)