Modulation

Chapter 15

Modulation

• Process that results in a shift of tonal center• Commonly called a key change

Closely Related Keys

• Keys that differ by no more than one accidental in the key signature and the relative major or minor

• Example: a minor– Closely related keys are: CM, em, dm, GM, and

FM

Types of Modulations

• Common Chord Modulation– Uses a pivot chord that belongs to both keys– Example: vi in DM also functions as the ii in AM

• Phrase Modulation– One phrase cadences in the original key– The next phrase begins in the new key

• Chromatic Modulation– One chord tone is raised by ½ step in one voice to

introduce the new key– No common chord is used

Harmonizing Modulating Melodies

• Identify the possible keys based on the key signature and its closely related keys

• Identify the cadences in those possible keys• Identify the possible chords for each melody note• Choose the harmonic progression that makes the

most sense• Identify the harmonic rhythm• Write a bass line• Add alto and tenor lines and non-harmonics

Harmonizing a Modulating Melody

• Things to consider:– 1. Circle progression is important in establishing

the key, especially after a modulation– 2. Try to use a common chord when possible.– 3. Start with the cadence and move backward

through the melody.