a few edits I'd like to make:
It's not entirely good to say that every song that one makes should be based on chords.
A good example that many can relate to is Koji Kondo. His style of composition is has
a great combination of romantic and late modern music. Although his melodies in the
Zelda series are amazing, some of his songs are completely reliant on the melodies
and the chords seem to just be a shadow for the various melodies. Playing the chords
alone, you might realize that it's often parallel motion which was popularized in the late
romantic/impressionist era (late 1800's - early 1900's).
I wouldn't completely advocate using 4 good chords repeated and calling it a decent
chord progression.
When you say something like "4 semitones up from A", that would actually equal to
C#. (A# - B - C - C#). I prefer to call semitones, 'halfsteps', so I'm gonna call them that for
this post.
So really, a minor chord is created by the root, 3 halfsteps up, and then 4
halfsteps above the previous.
Major chords are based on the root, 4 halfsteps up, and 3 halfsteps above the previous.
You might also want to explain the difference between minor and major chords, although
that sort of thing can best be interpreted by playing them.
For Chord progressions, it's good to teach them good resolving chords back into the
tonic, but then you'd have to explain roman numeral chord analysis.
telling people not to use chords outside of their key sig scale isn't a very good idea. It
restricts the potential of a piece's originality and it could hinder their ability to express their
intentions in more variant ways. Using notes outside of ur scale can be really helpful to your
piece is you're trying to incorporate things like chromaticism (a chromatic scale is a scale
where you just go up from any note up only in halfsteps) and dissonance.
A good example of both of those can be found in the middle section of my piano solo piece, Butterfly voice starting at 0:38.
I used it in that segment to get that feeling of struggling for love unabashedly.
The melody section of your tutorial, I just don't agree with but the idea of using the 1, 2, 3, 5 notes
of ur key's scale is a good start for any new composer.
To explain key completely, you need to go through teaching the circle of fifths/fourths, which is no
fun so I don't blame you for omitting that haha
Great start to a new music theory thread. I hope more people add on to this!