In the last lesson, we altered one of the intervals between the notes of a scale but there are many other ways to build different scales: actually, we’re not even stuck with 7 notes since one of the most popular scales on the guitar just has five.

If we take a minor scale and we drop the second and sixth degrees (the dark dots), the five remaining notes will form a Pentatonic Minor scale, the main ingredient of most Rock and Blues solos.

Minor Scale

Pentatonic Scale

The pentatonic shape is easy to play and easy to remember and avoiding those notes will not only give the scale its peculiar sound but also let you play in different harmonic contexts without worrying too much.

We can also play Major Pentatonic scales just remembering the old index/pinky trick: A minor pentatonic has exactly the same shape and fret position as C Major pentatonic.

We can also think of the pentatonic as the backbone to build different 7 note scales: if we reverse the process and add back in those two notes, we’ll get our minor scale back.

But we coulsìd also add different notes with interesting results: adding a Major 6th and a Second will give us a Dorian scale (what's that?).

But one of the most interesting scales we can create in this way is the Blues scale. Let’s add a flat fifth to the pentatonic:

I also like to add the Major 7th as a passing note (here in a paler shade of gray) though some say that the flat 5th is enough to define the Blues scale, one of the greatest tools a guitarist can use.

We can build scales with different numbers of notes and different intervals: the Whole Tone scale has six notes and all the intervals are (surprise, surprise!) whole tones while the Chromatic scale has 12 notes, all a half-tone apart.

We won’t go into the details of all the scales but, in the next section, we will learn how scales generate chords and what is the relationship that binds them.