Scales on the guitar

A scale is a series of notes in order, from the lowest to the highest, that sound good together. Melodies and solos are made with them, and chords come from them. Each scale has a formula, and that formula is the same no matter which note you start on.

The major scale

The major scale is the best known: C D E F G A B. Between each note and the next there is a whole step (W, 2 half steps, 2 frets) or a half step (H, 1 half step, 1 fret). The formula is W-W-H-W-W-W-H: there is a half step only from E to F and from B to C.

Each note of the scale is a degree, numbered 1 to 7 from the root: 1 is the root, 3 is the third, 5 is the fifth... These are the intervals from the Intervals lesson: in the major scale, degree 3 is a major third from the root and 5 is a perfect fifth.

Since the formula does not change, you can build the major scale from any note. From D it gives D E F# G A B C#: sharps appear so the same formula of whole and half steps repeats. Try it in the tool.

Build the major scale

Choose a root and move step by step along a single string: each step adds a whole step (W, two frets) or a half step (H, one fret), until the scale is complete.

The natural minor scale and relatives

The natural minor scale has the formula 1 2 b3 4 5 b6 b7: the third, sixth and seventh are a half step lower than in the major. It sounds more serious or sad. A natural minor is A B C D E F G.

Look: these are the same notes as C major. A minor is the relative minor of C major, and C major is the relative major of A minor. They have the same notes, but the minor starts on A, which is why it sounds different. The relative minor always starts on degree 6 of the major scale.

The pentatonic scales

Penta means five: these are 5-note scales. The major pentatonic comes from removing the 4 and the 7 from the major scale (degrees 1 2 3 5 6). The minor pentatonic comes from removing the 2 and the b6 from the natural minor (degrees 1 b3 4 5 b7). A minor pentatonic is A C D E G.

They are the most used for improvising because they have no half steps between their notes, which is where they clash most with chords. It is hard for a note to sound wrong, and their shape on the fretboard is easy to remember.

The blues scale

The blues scale is the minor pentatonic with one more note: the b5 (degrees 1 b3 4 b5 5 b7). That note is called the “blue note”: it sounds tense and expressive, and it is used as a passing note between the 4 and the 5. A blues is A C D Eb E G.

The harmonic minor

The harmonic minor is the natural minor with the seventh raised a half step (1 2 b3 4 5 b6 7). It exists so the chord on degree V is major or a seventh chord, which pushes more strongly toward the chord on degree I. A harmonic minor ends on G#: A B C D E F G#. We only mention it here.

See a scale on the fretboard

Choose a root (with the # / b switch) and a scale type. The fretboard shows all the notes of the scale from fret 0 to 12, with the root highlighted. You can see the note names or the degrees, and listen to the scale.

Compare two scales

Put two scales with the same root on the same fretboard and see which notes they share and which belong to only one. With A natural minor and A minor pentatonic you can see where the pentatonic comes from: it is the notes of the natural minor without the 2 and the b6.