How to change key in music or modulation is a fundamental technique that allows composers to create harmonic interest and variety within a piece. Modulation can be achieved in many different ways, and in this article, we will explore some of the most common modulation techniques used in classical music. We will also provide examples in the key of C major to help illustrate each technique.
1. Change Key from the Tonic Major to the Dominant
The modulation to the dominant from the tonic major is a common modulation technique in classical music, where the music changes key to the dominant key 5 notes above the tonic. For example, a composition in C major may modulate to G major, the dominant key. This modulation is often achieved through the use of a pivot chord or secondary dominant chords.
What is a Pivot Chord?
A pivot chord is a chord that is used to modulate or change key from one key to another. It is called a “pivot” chord because it serves as a common chord that is present in both the original key and the key to which the music is modulating. By using a pivot chord, the composer is able to smoothly transition from one key to another without the change sounding abrupt or jarring.
What is a secondary dominant chord?
A secondary dominant chord is a type of chord that is used to temporarily tonicize a non-tonic chord in a chord progression. It is called a “secondary” dominant because it functions as a dominant chord in a key other than the tonic key of the overall progression.
So how do we Modulate to the Dominant?
In the key of C major, the dominant key is G major. There are several ways to modulate or change key from C major to G major. Here are some examples:
Modulating from C Major to G Major using Pivot Chord:
Am is 6 in in C and 2 in G
Note difference between scale of C and G is the F#
- Am7 (pivot 6th) – D9 – G (2,5,1 ) in new key
- G# dim – Am – D – G (variation 1 on the above using a G#)
- E7 (pivot 3rd) – Am – D – G (variation 2 on the above using G#, (3, 6, 5. 1) in new key)
- Bm7 (pivot 7th) – C Major7 – D9 – G (6, 4, 5, 1) in new key
- Eb – F – G
2. Change Key to the Sub-Dominant
The modulation to the sub-dominant is a common modulation technique in classical music, where the music changes key to the sub-dominant key.
For example, a composition in C major may modulate to F major, the sub-dominant key or four notes above the tonic of C. Here are some examples:
The note difference between C and F major is the Bb.
- Gm – C7 – F ( 2,5,1 ) in new key or F# dim , Gm – C7 – F
- G7 – C7 – F
- Bb – C7 – F ( 4,5,1) in new key
- C7 – F ( 5,1) in new key
3. Change Key to the Super-Tonic
The supertonic is the second degree of the scale. In C major this would be either D major or D Minor. So, to modulate to D Minor
Modulating Notes in D Minor are Bb and C#
Modulating Chords are Gm and A
Pivot Chords are C, Dm, F and G
1. Em (3 in old key) – A7 – Dm ( 2,5,1) in new key
2. D# dim , E , A7 – Dm
3. B7 – Em7 – A7 – Dm ( 6,2,5,1 in new key)
4. G – A7 – D (4,5,1)
5. Bb – A7 – Dm (
To D Major
Modulating notes are Bb and C# – all the above
F# dim – Gm – A7 – D (4, 5,1)
3. Modulate to the Mediant
The supertonic is the third degree of the scale. In C major this would be either E major or E Minor. Modulate to E Minor.
E minor has two modulating notes a D# and F# and 1 modulating chord B
Possible Pivot chords are C, Em and Am
- F#m – B7 -Em (2, 5, 1) in new key
- F#m – E -B7 – Em ( 2, 1 , 5, 1) in new key
- Am – B7 – Em ( 1,5,1)
4. Modulate to the Sub-Mediant
The sub-mediant is the sixth degree of the scale. In C major this would be either A Minor or A Major. Modulate to A Minor.
Modulating notes are F# and G#
Pivot Chords are C, Dm, F, Am, B dim
Modulating chords are D and E
- Am -E7 – Am (1,5,1)
- Dm – E7 – Am (4,5,1)
- B7 – E7 – Am (2,5,1)
Summing Up
In conclusion, modulations are an essential tool for composers to create harmonic interest and variety within their compositions. The three most common modulation techniques in classical music are modulation to the dominant, modulation to the relative major/minor, and modulation to the mediant. By mastering these techniques, you can take your music to new heights and explore new harmonic territory.
