I reference “key” and “minor scale” in the post on solfège https://functionalanalysis.blog/2017/06/13/solfege/ , but now we’re going to go into it a little bit more.
A key is a framework for organizing notes in a tonal hierarchy. Read about tonality here: https://functionalanalysis.blog/2017/09/26/tonality/
Keys are centered around a tonic pitch and tonic chord. This chord/note is the name of the key. So if something is in D minor, the note D is the tonic note, and D minor (D F A) is the tonic chord. A minor scale starts on tonic (do) and goes up in the sequence whole step, half step, whole, whole, half, whole, whole (whwwhww) ending on the same note we started, but up an octave. Using D that comes out to the notes
D E F G A B♭ C D
do re me fa so le te do
Now minor is a little more complicated than major. The natural minor scale, shown above, is not how most music in minor behaves harmonically, with chords. As a youngster, I learned THREE minor scales in my piano lessons, natural, harmonic, and melodic.
Natural: do re me fa so le te do
Harmonic: do re me fa so le ti do
Melodic: do re me fa so la ti do te le so fa me re do
Now, it isn’t super often that you find an entire scale of any of these in music in entirety. It’s just that when using chords, the flat 7, te (C in D minor), is often switched for ti, (C#) to create tension toward the tonic. (harmonic = chords) But, melodically, trying to sing or play le up to ti is awkward, so a melody line might adjust to la ti borrowed from major going up, and then have te le going down.
The ti do motion still helps us recognize tonic (the reason why it is harmonically borrowed from major) and the minor thirds do me, and fa le help us recognize minor.
Here is a piece by Amy Beach in D minor: https://www.youtube.com/watch?v=KQyfAdcHlOU
Here is a piece by Nadia Boulanger in A minor: https://www.youtube.com/watch?v=i8KQ1O1Gjys&index=2&list=PLCVjtztz5wjQ0QXggwsnS0xydCgrKYjw8
cello part: http://musictheoryexamplesbywomen.com/examples/3-pieces-for-cello-and-piano-no-2-nadia-boulanger/
Pieces in minor keys end up having more accidentals and notes from outside the key, partially because the nature of the harmonic/melodic switch seen above. This sometimes means that minor sounds more “exotic.” Minor keys do not have to be sad!
I’m going to get to key signatures, part of how we notate keys, next. Maybe even tomorrow. Remember that something can be in a key that does not match its key signature!