What is a Scale? A basic understanding of what scales and arpeggios are.


According to Encyclopedia Britannica, a scale is a “graduated sequence of notes, tones or intervals dividing an octave”.

A scale can either be ascending or descending and the type of scale is determined by the interval, or the distance, between one note and the next.


Scales have been around since the origins of music and can take on many forms. The most ‘common’ scales you are likely to see when playing in a classical style (jazz and other forms of music have their own set of scales) are:

  • Major Scales
  • Minor Scales – Natural, Melodic and Harmonic
  • Arpeggios
  • Broken Chords
  • Chromatic Scales
  • Whole Tone Scale

Major scales

A major scale is arguably the most common type of scale used in Western music today. Like all scales, what makes a major scale sound as it does is the way it is structured.

Every major scale consists of 7 notes plus the first note repeated an octave higher (8 in total). The scale can be split into two halves. Each half is known as TETRACHORD (a scale of 4 notes with the interval between the first note and the last being a perfect 4th). Both tetrachords are identical in structure, as can be seen below:

In a major scale the 3rd and 4th notes of each tetrachord are a SEMITONE apart (indicated by the slurs). Therefore, every major scale has a semitone between degrees of the scale 3 & 4 and 7 & 8.

Minor Scales

Minor scales can seem confusing to anyone starting out with scales. However, they are no more complicated than thinking of them as major scales starting on the ‘wrong’ note. That wrong note happens to be a MINOR 3RD (or 3 semitones) below the major scale key note.

What’s important to note here is that every major scale has a related minor scale (i.e. they share the same key signature), e.g. C Major (no sharps or flats) is related to A Minor (no sharps or flats) and A is a minor 3rd, or 3 semitones, below C.

What makes minor scales more confusing is there are three forms of the minor scale:

  • NATURAL Minor
  • HARMONIC Minor
  • MELODIC Minor

The NATURAL minor scale is as we have described above – the major scale beginning a minor 3rd below the related major scale.

The HARMONIC minor scale is the same ascending and descending. However, the 7th note is sharpened both on the way up and on the way down. This creates a strange ‘Arabic’ sound due to the extended interval, an AUGMENTED 2nd, between the 6th and 7th degrees of the scale.

The MELODIC minor scale is different going up from coming down. On the way up the 6th and 7th degrees of the scale are sharpened and on the way down the 6th and 7th notes are flattened – the descending scale becomes the NATURAL minor scale.


An arpeggio is the notes of a chord played in sequence either ascending or descending.

Arpeggios can be in the following formats:

  • Major
  • Minor
  • Dominant 7th
  • Diminished 7th

A MAJOR arpeggio consists of the notes of a major chord. For example, C Major arpeggio would consist of the notes C – E – G. Similarly, a MINOR arpeggio consists of the notes of the minor chord – A Minor arpeggio would consist of the notes A – C – E.

A DOMINANT 7TH arpeggio is made up of 4 notes, with the first three notes forming a major triad and the fourth note being a minor 7th from the root. A dominant 7th will always be asked ‘in the key of…’ as the root of the chord is the dominant (or the 5th) of the key. For example, a dominant 7th in the key of C would consist of the notes G – B – D – F (the 7th) where G is the dominant in the key of C (5 notes up). The dominant 7th in the key of G would consist of the notes D – F# – A – C where the note D is the dominant (or the 5th) in the key of G.

A DIMINISHED 7TH arpeggio is, again, made up of 4 notes. The chord is made up of a diminished chord plus a diminished 7th. The easiest way to work out a diminished 7th chord is to build it up as a stacked series of minor 3rds. For example, a diminished 7th beginning on C would consist of the

notes C – Eb – Gb – Bbb (Rather than Bbb (B Double Flat), sometimes it is easier to think of the note A although theoretically this is incorrect) where the interval between each note is a minor 3rd


Unlike the major and minor scales which are known as diatonic scales, a CHROMATIC SCALE is a series of twelve tones (total number of notes within an octave range) either ascending or descending with each pitch a semitone apart.


A whole tone scale is a series of notes either ascending or descending where the interval between each note is a whole tone, or two semitones.