Friday, October 21, 2011

4-String Modes, Rooted on 5th String

When 4-string mode forms are rooted on the 5th string, they lose their symmetry. This is because the interval pattern of the strings is asymmetrical. That is, the interval pattern of the upper four strings (4-3-2-1, from low to high), the interval pattern is Perf. 4th / Maj 3rd / Perf. 4th, which is symmetrical. However the interval pattern of the four middle strings (5-4-3-2) is Perf. 4th / Perf. 4th / Maj 3rd, which is asymmetrical. So the patterns which span these four strings are asymmetrical.

Interestingly, three of these patterns - Mixolydian, Aeolian and Dorian - though lacking the rotational symmetry of the standard module forms, share the same silhouette;
The diagram above shows the key of G. Below you can see the Dorian and Mixolydian modes in the key of C;
The Ionian and Phrygian modes, which are a symmetrical module in the upper and lower strings, are very different in the middle four strings;
Likewise, the Lydian/Locrian module becomes a mixed bag;

All contents of this blog are © Mark Newstetter

No comments: