Understanding scales

Before moving on to scales, let’s first select a suitable space. Among the selectable spaces there is one that is particularly useful for understanding the concept of a scale, which is Octaves [1:12]. This space has a row for each of the 9 octaves, with each octave containing 12 semitone columns.

Now let’s choose a scale to apply to this space. You can control the scale using the scale parameter in tonespace.

Shown above is the chromatic scale, which is just a fancy word for saying that all notes are allowed for playing [2]. So there are no black cells here, only colored ones.

Musicians do not often use the chromatic scale, because if you would use all of these notes, it is possible to select two or more notes that do not sound well together (they are dissonant). Therefore, it is standard procedure to throw away a bunch of notes from each octave and only work with the remaining set. Such a set we call a scale. Notes within a scale tend to sound pleasant when played together.

For example, let’s choose another scale called the Major scale, also known as the Ionian scale. By applying the major scale, some columns are blackened in the space. These won’t react any more when you click them with the mouse. Their notes are forbidden.

The picture above makes clear what a scale really is : it is a set of note offsets, or intervals, that defines which are the “good” notes. For the major scale these intervals are [0 2 4 5 7 9 11] [3]. When these seven intervals are applied to the octave of middle C, it means we only get to keep midi notes 60+0, 60+2, 60+4, 60+5, 60+7, 60+9 and 60+11.

The major scale happens to contain 7 intervals, yielding 7 midi notes when added to the midi start note of the octave. Many other scales do too. But there are also scales with just 5 notes (e.g. pentatonic scales). There is no hard rule about how many notes there can be in a scale. You have to find a balance: if there are too many, dissonances occur more easily. If there are too few, less variation can be used in the chords and melody.