The FRETPAL app is an amazing tool that lets you explore and master the whole guitar fretboard in a fun and easy way.

You can learn how to play 3 and 4 note CHORDS and their INVERSIONS, the MAJOR and MINOR scale and their diatonic MODES, the MAJOR and MINOR pentatonic scales, the BLUES scales, how to mix the MAJOR and MINOR pentatonic scales, the formation and use of MODAL pentatonics, and how to play root and inverted ARPEGGIOS.

The FRETPAL app uses a unique colour and shape system that helps you to move around the guitar fretboard HORIZONTALLY, VERTICALLY and DIAGONALLY. 

This shows you many different patterns that you can apply to have COMPLETE control over the entire guitar fretboard.

This manual will guide you on how to use and get the most out of the FRETPAL app.

However, this manual is not designed to teach you music theory or guitar playing technique(s).

There are plenty of videos, courses, books, e-books and other softwares that can teach you music theory and guitar playing technique(s) at any level you want.

Many of these will be tailored to the kind of music you want to play.

No matter what your music theory knowledge or guitar playing skills or music style preference are, the FRETPAL app is here to help you to master the whole guitar fretboard.


In western music, the “chromatic scale” is made up of 12 individual pitches, each one a half-tone (or semi-tone if you prefer) above or below each other.

Considering the word “CHROMATIC” is derived from the Greek word “CHROMA” which means COLOUR, the chromatic scale diagram above is not at all colourful…

Now, the most important and commonly used scale in western music is the MAJOR scale.

 In the key of C MAJOR, the MAJOR scale (or IONIAN mode) contains the notes C, D, E, F, G, A and B.

As you can see on the chromatic scale diagram above, the C MAJOR scale contains no sharps or flats (accidentals), therefore, it is the simplest form of a MAJOR scale.

If we map out the position of all the notes of the C MAJOR scale on to the guitar fretboard (in standard tuning), this is how it looks:

Without any distinctive colours or shapes, all the notes look the same – there is nothing to make each note look unique or easily identifiable.

A typical marking system on the guitar fretboard like the one below gives us little help to navigate the fretboard effectively:

Apart from the markers at the 12th and 24th fret which mark the start or end of an octave, all the other markers show you is where the 3rd, 5th, 7th, 9th, 15th, 17th, 19th and 21st frets are.

Even if you have thorough knowledge of the fretboard, these markers are of little practical use to us.

However, there is a far better solution when we use:-


When Sir Isaac Newton first identified the individual colours of the “visible spectrum” of the rainbow, it was suggested by other scientists that he was so keen to make an analogy with music – and in particular with the musical octave (with its 7 distinct intervals), that he added an “extra” colour INDIGO just to make the analogy fit.

In fact, there is still some debate going on today as to whether or not INDIGO exists as a separate colour in the rainbow.

Be that as it may, the 7 individual colours: RED, ORANGE, YELLOW, GREEN, BLUE, INDIGO and VIOLET that Sir Isaac defined when related directly to the intervals of the MAJOR scale are indeed a fantastic way to identify each of the individual intervals of the musical octave.

 Whether INDIGO exists as a separate colour or not.

If we transfer these colours into our “chromatic” scale we can see how it immediately helps us.

We can also assign shapes to each of the intervals that will help us quickly identify the MODES of the MAJOR and MINOR scale:


The colour and shape of each of the notes immediately IDENTIFIES the root and starting point of all of the patterns of the MODES of the MAJOR and MINOR scale.


First up is the MAJOR scale (which is also called the IONIAN mode) and starts with the RED square.

The “relative” or “natural” MINOR scale (also called the AEOLIAN mode) starts with the INDIGO square.

Please remember that IONIAN, DORIAN, PHRYGIAN, LYDIAN, MIXOLYDIAN, AEOLIAN and LOCRIAN are all MODES of the parent MAJOR or MINOR scale.

It is not correct to call the IONIAN or AEOLIAN mode the IONIAN or AEOLIAN scale.

 However, as they are “relative” or “natural” to each other, it is correct to refer to the IONIAN and AEOLIAN mode in ANY key as the MAJOR or MINOR scale respectively.


The DORIAN and PHRYGIAN modes start on the ORANGE and YELLOW circles respectively.

Whilst these 2 MODES are both MINOR quality modes (that is, they contain a minor 3rd note), they are NEITHER “relative” nor “natural” minor scales. 

It is only the AEOLIAN mode (or natural/relative MINOR scale) that has this relationship to the “parent” IONIAN mode (or natural/relative MAJOR scale).


The GREEN diamond shape represents the starting point of the LYDIAN mode (which is major in quality as it contains a major 3rd interval).

 The VIOLET diamond shape represents the LOCRIAN mode (which is neither of fully major nor minor quality as it contains a minor 3rd interval AND a FLATTENED 5th note, that is, the 3rd and 5th note is separated by another consecutive minor 3rd interval). 

The distinct diamond shapes were chosen because they are immediately identifiable as the 2 intervals that are  OMITTED when playing the MAJOR/MINOR pentatonic, BLUES or MAJOR BLUES scale patterns.

That is, to form a C major pentatonic scale, the 4th note (F) and 7th note (B) are omitted from the C major scale/C IONIAN mode – (C, D, E, F, G, A and B), which leaves the notes C, D, E, G and A.

To form an A minor pentatonic scale, the 2nd note (B) and 6th note (F) are omitted from the A minor/A AEOLIAN mode – (A, B, C, D, E, F and G), which leaves the notes A, C, D, E and G.


Finally, the MIXOLYDIAN mode starts on the BLUE circle. 

The MIXOLYDIAN mode is of MAJOR quality because it contains a major 3rd interval.

 However, the MIXOLYDIAN mode also contains a flattened 7th note, which gives this MODE and the chords formed from it a unique character and sound.

Here are a few interesting observations.

The MIXOLYDIAN mode and the chords made from it are extensively used in BLUES music.

Using the rainbow colour system, we could call the MIXOLYDIAN mode the “BLUE” mode as it always starts on the 5th degree of any MAJOR scale.

Is that just nothing more than mere coincidence?

Also, the 3 PRIMARY colours of LIGHT are RED, GREEN and BLUE.

These PRIMARY colours relate to the 3 MAJOR quality modes:

That is, the IONIAN, LYDIAN and MIXOLYDIAN modes.

It is very clear to see that the 7 colour rainbow as identified by Sir Isaac Newton is the perfect analogy for the musical octave, whether INDIGO is a separate colour of the rainbow or not.

If it were not for Sir Isaac, the FRETPAL app would probably never have been made.

Therefore, FRETPAL is dedicated to him with the deepest respect and gratitude.