Chords & progressions
A chord is a small stack of scale notes; a progression is the feeling created when the stack moves.
A chord is several notes heard as one object. A progression is what happens when those objects create home, departure and return.
Listen for: Every chord jumps back to its basic shape.
Stack every other scale note
Take one scale degree, skip the next, add the next, skip again, add one more: that three-note stack is a triad. PlasticSynth's Progression and Strum instruments build the diatonic triads for the current key, so every button belongs to the same musical world.
The tonic chord feels like home. Other chords create different amounts of distance and tension. A progression feels finished when that tension returns to a convincing home.
Move the people, not the building
A chord can be reordered without changing its name. Choose an inversion whose notes are close to the previous chord. This voice leading turns block jumps into several small melodic lines.