Wednesday, January 24, 2018

Diagonal Chromatic Blocks - Part I

When you play a Major 7th Chord in the root voicing on the top four strings it forms a diagonal line with a note in each of the four strings and spanning four frets. In the diagram below, you see four consecutive major 7th chords of the type just described:

... This block comprises sixteen notes and can be played in any fret position. Notice that the 7th of the fourth chord in the block is on the same fret as the Root of the first chord. Also, due to the diagonal shape of each chord, the four-chord sequence spans seven frets in total.

Now lets look at it with note names:
The same block is now assigned to a specific fret position. In this case it's positioned so that the first chord is Fmaj7. As long as the block is treated as a series of chords, the note names will follow that scheme ... for example; a G major 7th cord has the notes G B D F#, so if we use the grid as a major 7th map, then F# is not Gb. But if we only want to show the chromaticism of each row of notes, then it might be clearer to use only sharps or only flats for every note which isn't a natural tone:

Now if we apply this principle to the entire fretboard — keeping the idea of a four-chord block as our template — we will get three blocks running from the open position all the way to the 14th fret where E is the Root note of the last diagonal chord:

The blocks are each numbered 1 2 3 4 for the diagonals. The bold vertical bars are on the 3rd7th and 11th frets.
Now lets look at a single block from a different perspective.

Looking at all the notes of a block, we'll see that it contains all 12 notes of the system, some of them more than once, some only once. If we use F as the starting note, we can see that F, Gb, G and C appear twice in the block and that the remaining eight notes only happen once:
Notes which occur twice in the pattern are shown in the L shapes.

... Furthermore, of the four repeating notes, three of them: F, Gb and G, form octaves while one: C, is a unison. The eight unique notes form two chromatic runs: Ab, A, Bb, B and Db, D, Eb, E, with a whole-step: B — Db (or B— C#), between the two. 

Below you can see the entire fretboard with the duplicate notes highlighted:

The groups of unique notes look this:

... and like this in all three blocks:

 These blocks are not "in" any particular key. There are may ways to organize the notes within a chromatic block to visualize particular keys. Well look at that in the next post.

This diagram shows the notes grouped into the Unique-Notes and the Clone-Notes across the fretboard.

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