Similar to the way that chords define the harmonic structure (notes playing together) of a piece of music, scales define the melodic structure (notes in sequence) of music by specifying which notes it contains.
Sometimes a whole song uses notes from a single scale, but it is often more useful to work with a series of scales or key centres, each of which corresponds to a chord in the song.
Scale Types
As with chords, a particular scale (eg. Eb Major) is made up from its root note (Eb) and scale type (Major). A scale type specifies a number of notes, each of them a particular interval from the root, or starting note.
There are many different scale types, each with a different sound or mood. For examples, see the standard scale types that are supplied with ChordWizard. These can be individually activated or added to with the Scale Types page in Library Options.
By far the most common scale type in western music is the Major scale. When played in sequence, the notes of the Major scale make the famous do-re-mi-fa-so-la-ti-do sound. The Major scale is widely used even in harmony, where its note positions give names to the degrees of a chord type.
For example, the maj7 chord type contains the degrees 1-3-5-7. They are named like this because the intervals of these degrees from the root note of the chord is the same as the intervals of the 1st, 3rd, 5th and 7th notes of the Major scale.
Scales and Songs
Usually, in a song or a piece of music, the melody is made up from just one scale, perhaps with some accidental notes thrown in. There is also a chord sequence that provides backing for the melody by defining the changing harmony in the song.
Often though, in more complex music like jazz, there is more than one scale in a song, giving it a changing melodic and harmonic structure. Sometimes the scale will change with every chord change. This makes the music more difficult to play, but it can greatly enhance its richness and expressiveness.
See Also
