Catullus64
2022-03-23, 04:42 PM
This post is authored by a mere amateur, and a middling one at that, in music theory. Forgive my errors and misunderstandings. Musicians and musicologists, be kind.
What makes a particular piece "in" a given key? This isn't a question about notation; practically speaking, the answer is "because the key signature says so". I know how the circle of fifths works and I understand (in theory) how individual chords fit within the structure of a diatonic scale.
But the notation doesn't restrict the reality of what gets played. If a given piece is notionally in one key, but contains so many accidentals that they outnumber the in-key notes, in what sense can the piece be said to be "in" that key? At a certain point, I feel that the tonic, which gives the key its name, ceases to actually function if the music departs too much from its scale; but where is that point? Is it simply when the composer decides he'll save ink by notating a key change rather than adding sharps and flats? (The non-blue version: are keys just tools for composers to organize their compositions, rather than structures innate to the music itself?)
An instance which I think exemplifies this quandry for me is the Picardy third, wherein a piece in a minor key terminates with a chord from the corresponding major key, accomplished by moving the middle pitch of a minor triad by a semitone. If a piece can be played entirely in one key, and yet have a satisfactory resolution in another, what determines that it was "in" the minor key the whole time?
What makes a particular piece "in" a given key? This isn't a question about notation; practically speaking, the answer is "because the key signature says so". I know how the circle of fifths works and I understand (in theory) how individual chords fit within the structure of a diatonic scale.
But the notation doesn't restrict the reality of what gets played. If a given piece is notionally in one key, but contains so many accidentals that they outnumber the in-key notes, in what sense can the piece be said to be "in" that key? At a certain point, I feel that the tonic, which gives the key its name, ceases to actually function if the music departs too much from its scale; but where is that point? Is it simply when the composer decides he'll save ink by notating a key change rather than adding sharps and flats? (The non-blue version: are keys just tools for composers to organize their compositions, rather than structures innate to the music itself?)
An instance which I think exemplifies this quandry for me is the Picardy third, wherein a piece in a minor key terminates with a chord from the corresponding major key, accomplished by moving the middle pitch of a minor triad by a semitone. If a piece can be played entirely in one key, and yet have a satisfactory resolution in another, what determines that it was "in" the minor key the whole time?