Scale degrees can refer to notes within a scale or chords within a key. They are written as numbers (usually Roman numerals) which describe how far a note is from the root note of the scale or how far the chord is from the start of the key signature. For example, in the Key of C the C chord is I and the F chord is IV because F is the fourth note in the C major scale. As an aid to transposing, Jazz standards are often notated as scale degrees.

The tonality of the diatonic chords in a key are:

I Major
II Minor
III Minor
IV Major
V Major
VI Minor
VII Half-diminished

There are differences between all of these major and minor chords. These differences are found in the other chord tones. There are even more notes to draw from when you look at the scale tones which belong to each mode.

The Roman numerals assigned to each chord of the scale also help us with identifying the different types of chord available in a major scale. I, IV and V are classed as the Primary chord types because they are the strongest sounding chords in any key. These chords are the main chords used in most compositions. The II, III, VI, and VII are classed as the Secondary chord types because they are the weaker sounding chords of any key and are used to connect and support the Primary chords within a composition.

Every major scale can be looked at this way and every major scale will also have the same combination of major, minor and half diminished chord types:

Example 73a

The Scale Degree Box

By numbering the notes in the same way as the Roman numerals but using common numbers, the scale degree way of thinking can give you the ability to transpose one group of numbers and alterations throughout all twelve keys.

C Dorian Mode

Example 73b

Transposition

Transposition is when you take a melody, chord progression or tune in one key signature and then apply or transpose it to another key signature. This is done by noting the scale degrees and deviations of the first key and applying them to the second key with the same rhythm. This skill is extremely useful because riffs, licks, tunes, chords, etc. that you learn in one key can be applied to all twelve keys.

Example 73c

Some basic notes from C major in Example 73c are transposed to F major in Example 73d using the same scale degrees.