Forum: music.stackexchange.com
Tags: <theory><modulation>
Title: Do modulations from a major key to a mode count as 'key changes?'
Question: I was listening to Green Light by Lorde, during which there is a modulation from A major to the mixolydian mode. DOes that count as a 'key change' per se?

Answers:
sents: text: People have different viewpoints on this, but one prevailing view is that a modulation must change tonal center .
text: In other words, a move from A major to A Mixolydian is not a modulation, because the tonic (=tonal center) is still A.
text: As such, we just call this a "change of mode."
answer_details: author: music.stackexchange.com/users/21766/Richard
score: 6
sents: text: Is this all about the use of a bVII chord in the final choruses?
text: Just let it BE the bVII in the key of A. A chromatic chord doesn't necessarily imply a key change.
text: Think of a simple blues progression - A7, D7, A7, E7, D7, A7.
text: You have no problem with that being in the key of A, despite the Cnat and Gnat notes do you?
answer_details: author: music.stackexchange.com/users/17003/Laurence Payne
score: 3
sents: text: In the event of a modulation, the music is still with the same key signature, as modulations are generally a temporary move.
text: With a key change, the term says it all - the key has changed, it's not temporary, there needs to be a sign displaying the new key.
text: 'Borrowing', from parallel key and other modes with the same root - as in A major using A Dorian, A minor, A Mixolydian etc., is going to be a modulation, and there will be the necessary accidentals in place, with the feeling that the piece will eventually return to the original key.
text: Other common modulations are moving to a related key, a fourth or fifth away, and relative major/minor changes.
answer_details: author: music.stackexchange.com/users/2808/Tim
score: 2
sents: text: A key change occurs whenever the key signature changes.
text: This is pretty objective and quite different from a modulation, which can occur with or without a key change (often with accidentals).
text: If you are switching modes but not tonal center, I would not call that a modulation; I would call it "borrowing (from a parallel scale)."
answer_details: author: music.stackexchange.com/users/9774/John Wu
score: 1
sents: text: This is another example of terminology trying to put hard and fast lines where none exist.
text: If the "tonal center" changes for just one chord, it's not a modulation; if an entire movement is around a new tonal center, it's modulation.
text: But everything in between exists as well, and there's no convention (nor could there be reasonably) to say exactly when "modulation" occurs.
answer_details: author: music.stackexchange.com/users/26744/Scott Wallace
score: 1
sents: text: Changing from C Ionian to D Dorian is changing mode but isn't changing key.
text: Changing from C Ionian to D Phrygian is changing mode and changing Key.
text: More examples: D Dorian >
text: E Phrygian - Changing mode, not changing Key.
text: A
text: Aeolian
text: >
text: G Mixolydian - Changing mode, not changing Key.
text: D Dorian >
text: Db Lydian - Changing mode, changing Key.
text: F Aeolian
text: >
text: A Mixolydian - Changing mode, changing Key.
text: Another Example: Blue in green by Bill evans is... D Dorian is in Cmaj C Dorian
text: is in Bbmaj Bb Ionian
text: is in BbMaj
text: A Phrygian is in FMaj D Dorian is in Cmaj F Aeolian is in Abmaj
text: A mixolydian is in Dmaj The best modal music changes Key and mode.
text: Changing mode is not as weird as you think it's basically changing chords within a key.
text: The cool stuff comes when you change mode but to another key.
text: I've not listened to Green Light by Lorde but would assume it's just changing mode and not the key, which is kinda boring.
text: Also you could go: D dorian
text: > C dorian
text: But this is just a key change in my opinion and not a mode change.
answer_details: author: music.stackexchange.com/users/64579/Greg James
score: 0

Summary of the answers:
 In the event of a modulation, the music is still with the same key signature, as modulations are generally a temporary move. With a key change, the term says it all - the key has changed, it's not temporary, there needs to be a sign displaying the new key.  'Borrowing', from parallel key and other modes with the same root - as in A major using A Dorian, A minor, A Mixolydian etc., is going to be a modulation, and there will be the necessary accidentals in place, with the feeling that the piece will eventually return to the original key. Other common modulations are moving to a related key, a fourth or fifth away, and relative major/minor changes.
In the event of a modulation, the music is still with the same key signature, as modulations are generally a temporary move.