Moving between chords: the rules

Four lines, not a row of chords

Until now each chord stood on its own. In a progression every voice moves on to the next chord, so you are really writing four melodies at once. The rules all aim at one thing: four lines that are each easy to sing and that stay independent of each other.

• Always: the leading note in the soprano rises to the tonic; keep a note the two chords share in the same voice; move by step where you can; keep the upper voices within an octave of each other.
• Never: consecutive 5ths or octaves; a doubled leading note; an augmented interval in one part; voices that cross or overlap.

The next screens take one rule at a time, with the reason for it.