Bach Chorale - Modulations

Where can a major key modulate to?

For example with the home key being D major:

• Relative minor (B minor)

• The dominant (A major) + its relative minor (F# minor)

• Subdominant (G major) + its relative minor (E minor)

Where can a minor key modulate to?

For example with the home key being A minor:

• Relative major (C major)

• Dominant (E minor) + its relative major (G major)

• Subdominant (D minor) + its relative major (F major)

Types of Modulation

(3)

1. Pivot chord modulation (most common)

2. Phrase modulation

3. Sudden / Abrupt modulation

Pivot Chord Modulation

• A smooth change of key can be made using a pivot chord

• A pivot chord is a chord that belongs to both the new and home key.

• A pivot chord is normally followed by a chord of the dominant group in the new key (i.e V, V⁷ or vii^o7)

• However, if you spot a melody note that can only belong in the destination key then the chord before the note will be the pivot chord.

This is the most common type of modulation

Phrase Modulation

Occurs immediately after a cadence - So at the start of the phrase and lasts for the whole phrase:

-Easiest way to modulate, however can often be impossible to stay in the same key for a whole phrase from:

• Accidentls in the phrase that make the key of the next cadence impossible

• If the beginning of the phrase cannot be harmonised with straightforward chords using the destination key.

• If the key at the end of the previous phrase is too distant from the cadence key of the next phrase.

Sudden / Abrupt Modulation

A chord of the destination key’s dominant group (V, V⁷ or vii^o7) appears with no intervening pivot chord. Such as V, V⁷ or vii^o7 - 1 movement creates passing modulations.

• Frequently made by a note rising by semitone in the bass (which acts as the new leading not)

Avoid this as much as possible!

Recognising a Modulation

Accidentals

• If there is a note outside the key (sharp, flat or natural), then a modulation is often suggested.

• Scan the melody to see if this note reappears and find the related key.

• A new sharp (in a ‘sharp’ key) or a new natural (in a ‘flat’ key) is likely to be a new leading note.

• A new natural (in a ‘sharp key) or a new sharp (in a ‘flat’ key) is most likely the dominant 7th note of the new key

Leading not is not rising

• Check for a leading note that does not rise in the melody.

• Always check the cadence at the end of the phrase which will give clues on what to modulate to.

Checking a Modulation

1. Does it modulate to a related key (i.e. Dominant)

2. Check for a perfect cadence to establish the new key

3. Label the chords in the new key

4. DO NOT FORGET THE ACCIDENTALS

5. Which type of modulation is it

6. Remember it is better to start a modulation early rather than at a cadence.

7. Chorales often return to the home key at the end.