An Intensive Journey to Demystifying the Fretboard - Part 2

If you haven’t read yet, make sure to check the previous segment of the series:
Part 1 - Practising Scales with Creativity

I always find it fascinating how much colour we can squeeze out of combining just two notes together.

Traditionally, the most common use of the double stop is to add more weight and support to melodic lines. Therefore it’s our obligation to study them exhaustively since not only they can assist us with the further demystification of the fretboard but they are also quite useful compositional elements.

Within one octave can be found the intervals of the second, third and fourth as well as their inversions fifth, sixth and the seventh. It is very useful to think of these pairs of intervals as reflections on a mirror since their effects are similar and we deal mostly with how much space you leave between the voices.

The following happens when we invert the intervals:

Seconds become Sevenths and vice versa
Thirds become Sixths and vice versa
Fourths become Fifths and vice versa

Also:

Major intervals become Minor and vice versa
Diminished intervals become Augmented and vice versa
Perfect intervals remain Perfect

Bonus Info:

When Major or Perfect intervals become a half step larger are called Augmented
When Minor or Perfect intervals become a half step smaller is called Diminished

The diverse pool of emotions and colours that different intervals convey can be by a not so subtle margin subjective and therefore their uses differ across various cultures, centuries and genres of music.

It is generally accepted though that:

Thirds and a Sixths are consonant and colourful
Perfect Fourths and Fifths are tonally ambiguous
Seconds and Sevenths are dissonant and provide plentiful tension

Music with excessive use of dissonance can sometimes be alienating but contrarily music without tension and dissonance can quickly become boring and too convenient. A way to use dissonances in a more companionable tone is to hide dissonant intervals within a consonant texture so that they become less animating and dominant features of the overall music.

Things to do:

Explore all intervals in the same diagonal manner similar to the scales practising
Pause and try to think what each interval brings out to you
Create miniature works or improvise only with the use of double stops, why not restrict yourself to only one type of double stop
Find uses of double stops in the works of the composers you like and analyse them.

When practising intervals and double stop, my goal is to be able to recall any sound without much thinking and to be able to play anything, anytime and everywhere on the guitar!

After all, double stops are 66,6% triads.