2.14 Degrees I, IV and V: tonic, subdominant and dominant


Category: Harmony | Tags: Chords, Triads


In Chapter 2.12 Degrees: triads and scales, you’ve learned that a degree indicates the position of a chord in a scale. In this chapter, you will learn which degrees are most important. You’ll also learn that scale degrees have specific functions.

1. The primary degrees

Not all degrees in a scale are equally important. The most important degrees are called primary degrees, and the other four are called secondary degrees. The primary degrees are the first, fourth and fifth degree.


The first degree: the tonic

A triad built on the first tone (the tonic) of a scale - the first degree (I), is called the tonic.

The first degree is the most important one and has a stable character. It is the degree on which a piece of music (almost always) ends. The music "comes home," it sounds like a resting point. This is because the root of the first degree is also the tonic of the scale.


The fifth degree: the dominant

A triad built on the fifth tone (dominant tone) of a scale - the fifth degree (V), is called the dominant.

The fifth degree has an unstable character. The fifth degree brings tension and is often followed by the first degree. This is because the fifth degree contains two important tones from the scale that want to resolve to the tonic. The first one is the root of the fifth degree, which is the same tone as the dominant tone of the scale. The second one is the third of the fifth degree, which is the same tone as the leading tone of the scale. This makes the fifth degree often resolve to the first degree.


The fourth degree: the subdominant

A triad built on the fourth tone of a scale - the fourth degree (IV), is called the subdominant.

The fourth degree is a chord situated between the first and fifth degree. It doesn't have the stable character of a tonic, but, also doesn't have the tension of the dominant. The fourth degree can go in any direction, it can be followed by the tonic, but, also by the dominant. Or it can stay in its own position.



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Degrees I, IV and V in the C major scale.

note example

piano example

2. Chords have functions

In music, chords are never autonomous, they never stand alone. They follow each other in a logical way, giving coherence to the music. This coherence is dependant on chord functions. We mean by this that the functions have a certain character, such as tension or rest, they can sound stable or unstable, or, indeterminate. For example, a chord with an unstable character has the tendency, almost a magnetic pull towards a chord with a stable character. These chord functions are called tonic, subdominant, and dominant. You have already been introduced to these functions in 1. The primary degrees.

This functionality of chords is an important factor in music. It is very common in classical music (especially in the 18th and 19th centuries) but also in pop music, blues and jazz.

3. The secondary degrees

The second, third, sixth and seventh degrees are called secondary degrees.

Secondary degrees also have functions. For example, the sixth degree has a tonic function, the second degree a subdominant function, and the seventh degree a dominant function. You'll learn more about this later in level 5, level 6, and level 7.

4. Degrees and scales

In any scale, the degrees have the same function. If you play in the key of C major, then the fifth degree, the G-chord, has a dominant function. If you play in the key of G major, the fifth degree, the D-chord, also has a dominant function. Since this applies to every scale you learn, it is necessary to learn which chords belong to which degree for each scale. And, especially for the primary degrees. This is not only about theoretical knowledge but also a question of practice, so that you can play these chords on your instrument. Therefore, with each new scale you learn, there will also a chapter in which you can learn the primary degrees of the scale. The first chapter in which you can learn and practice primary degrees is Chapter 2.16 The primary degrees in C major.

5. Ear training: learn to recognize chord functions by ear

It is also possible to distinguish the different degrees and their functions by ear. Listen to three examples:

cd Degrees: tonic, subdominant and dominant | Musictheory.educationListen to I-IV-I, or tonic - subdominant - tonic

cd Degrees: tonic, subdominant and dominant | Musictheory.educationListen to I-V-I, or tonic - dominant - tonic

cd Degrees: tonic, subdominant and dominant | Musictheory.educationListen to IV-V-I, or subdominant - dominant - tonic

To learn to recognize the different degrees and chord functions by ear, a number of different exercises have been made for the enthusiast. These exercises are called Recognizing degrees, Notating degrees and Degrees and melody and can be found from level 2 to level 6.

Find out more about Recognizing degrees, Notating degrees and Degrees and melody in Chapter 2.25 Degrees: ear training.