Introduction

The degrees of a key correspond to the position of the note in the scale.

For example, in C major, the I^st degree is C, the II^nd is D, the III^rd is E, and so on, until the VII^th, which is B. When we return to C, we get back to the I^st degree.

Be careful, this is true only in C major. When changing the key (so the scale), we must start from the first note of the scale to count the corresponding degrees. Thus, in G major, the I^st degree is G, the II^nd is A, the III^rd is B, and so on, until the VII^th which is F. When we return to G, we get back to the I^st degree.

The degree is therefore relative to the key in which we are.

Degrees and harmony

At each degree corresponds a harmony, that is to say a three-note chord built on the degree in question, by a stack of thirds.

The following table shows the harmonies of each degrees of a major key. Degrees I, IV, and V form perfect major chords while degrees II, III, and VI form minor perfect chords. This means that, whatever the major key considered, the harmony of the IV^th degree will always be major, while that of the II^nd degree will always be minor.

Degrees are functions

Why number the notes of a scale? In fact, the degrees indicate the functions of the notes.

To understand this concept, let's make a small comparison with the language. In English, words have a nature and a function. For example, in the sentence "This flower is beautiful", the word "flower" is a name: it is its nature. The word "flower" is the subject of the sentence: it is its function. Let's take another sentence: "I like this flower". In this second sentence, the word "flower" is still a name: its nature has not changed. On the other hand, its function is in this case Direct Object. We thus see that the same word (or nominal group) can have different functions, without changing its nature.

Last update on 2021/05/07