8,720
edits
Changes
m
'''''G--0-------1-------2------'''''
no edit summary
{|class="wikitable"
!colspan="2"|
!colspan="3"| Key 2 Type<br>and number<br>of common<br>notes
|-
! Key 1 Type
* '''i => III''' - (Am => C, Em => G, B{{f}}m => D)
* '''i => {{s}}iv''' - (Ahm => D{{s}}hm)
{{top}}
== Modulation Methods ==
=== Common Chord ===
Uses a chord common to the source and destination keys to transition between them.
{{top}}
=== Enharmonic Chord ===
Even if two keys do not have the same chords in way of naming conventions, they may have chords that are enharmonically equivalent. For example, the keys of C{{s}} and C{{f}} have no chords in common by name. C{{s}} has only {{s}} chords and C{{f}} has only {{f}} chords. Yet, E{{f}}m and D{{s}}m are enharmonic, as are G{{b}} and F{{s}}.
{{top}}
=== Common Tone ===
A note common to the source and destination key is sustained during the transition. For example, a C ==> Em modulation could sustain the E in the I chord of C while moving to the i chord of Em, which also contains E.
{{top}}
=== Chromatic ===
E--3-------0-------0------
B--0-------0-------1------
D--0-------2-------2------
A--2-------2-------0------
Depending on the keys used, it may be more difficult to achieve the chromatic line with only the diatonic chords of the two keys. In these cases, we can resort to using a [[Borrowing Chords/Notes#Secondary Dominant|secondary dominant]] or some other non-diatonic chord.
{{top}}
=== Phrase ===
A phrase modulation avoids any transition whatsoever, occurring abruptly between two virtually independent phrases. The first phrase in the original key will end on a cadence, finding resolution and ending. The next phrase begins in the new key, with no harmonic or melodic bridge to ease the transition. This modulation is commonly between closely-related keys, preventing a completely disjointed feel. However, the transition is typically quite noticeable, which is the point of this modulation method.
{{top}}
=== Sequential/Rosalia ===
Cm B B{{f}}m A A{{f}}m G E{{f}}m A{{f}}m
Cm: i VII B{{f}}m: i VII A{{f}}m: i VII v i
{{top}}
=== Chain ===
For example, consider a modulation from C Major to E Major. These keys only share 3 notes in common, and are separated on the circle of fifths by 4 movements. They share no diatonic chords. Instead of trying to modulate directly between them, we can use a chain modulation. We could follow the circle of fifths, going major to major key until we reach E (C => G => D => A => E). Or we could shorten that by jumping every other 5th (C => D => E). C Major and D Major share the diatonic G Major chord. D Major and E Major share the diatonic A Major chord. This allows two common chord modulations to easily get from C Major to E Major without any disruptive transitions.
{{top}}
=== Parallel Key ===
[[Modes#Pitch Axis Theory|Pitch Axis Theory]][http://en.wikipedia.org/wiki/Pitch_axis_theory] is an extreme example of this. It uses chord progressions that all feature a common note - often this note is the root of every chord in the progression. The underlying chords are not diatonic to any one key. Instead, the scale used for melody/lead will change to conform with each chord.
{{top}}
== Why/When to Modulate? ==
=== Clarifying Song Structure by Contrasting Sections ===
{{top}}
=== Contrasting Themes within the same Section ===
{{top}}
=== Building Excitement ===
{{top}}
=== Creating Tension or Ambiguous Tonality ===
{{top}}
== Homework ==
* [[Voice Leading|Prev: Voice Leading]]
* [[Chromatic Chords|Next: Chromatic Chords]]
{{top}}
{{Advanced Lesson Crumbs|2}}
[[Category:Guitar]]