As mentioned earlier, most tracks need a harmonic context throughout the song, in order to generate a compatible arrangement of events.  This context is provided by either the Chords track or the Scales track.

This particularly applies to the Melody, Riff and Bass tracks, which cannot generate events in areas of a song where no chord or scale is defined.

Key Centres

For melody tracks, Songtrix can generate style events to suit any harmonic progression in the song.  To understand how, it will help if you review the Chord and Scale Relations tutorial first.

The process works by translating the style's defined events from their source key centre to that of the destination area in the song.

Let's take a concrete example.  Imagine the notes C-E-G being played in the Riff track of the style, where the C Major key centre is active.  These notes represent the first, third and fifth notes of the scale.

If this section of the style is to be used in the song where a G Dorian key centre is active, the notes will be translated respectively to G-Bb-D, which are the first, third and fifth notes of this destination scale.

In reality, the process is a little more complex than this, to accommodate well-formed melodies and accidental notes which are not part of the prevailing key centres.

But you should be able to see how the principle works, and how adjusting key centres affects the final notes generated.

Chords To Scales

If both the style and the song include Scales tracks defining the key centres of the song, then note translation when generating melody events works exactly as described in the previous section.

Often however, styles and songs do not contain Scales tracks.  In fact they are not strictly necessary, provided that Chords tracks are available instead.

This is because Songtrix is able to internally find related key centres for each chord in the Chords track if there is no Scales track to explicitly define them, and it uses these for the translation.

Most of the time, this works well, but there may be times when you prefer to include the Scales track in a song, to give you more control over the reharmonizing process.

Using Scales

If a song using styles includes a Scales track, then this is used instead of the Chords track for generating the autostyle events.

The Chords track has no direct effect on the process, although it may still play a part in selecting your scales, particularly if you are using Auto Select linking from the Chords to the Scales tracks.

If both Chords and Scales tracks are included, and they are linked in this way, then you are essentially seeing the same process that otherwise happens invisibly (as described above) when no Scales track is present.

The difference here is that while a key centre is still being chosen automatically, you can influence the harmonization process by selecting a different scale instead.

For example, a Cmaj chord (shown above) will usually result in the C Major scale being its related key centre, whether the Scales track is present or not.

If you include the Scales track, you have the opportunity to select an alternative related key centre instead, such as C Lydian.

You should always try to select a key centre with the same root note as the chord to prevent (possibly strange) harmonic inversions from occurring.