Melody on chord tones sounds resolved; on tensions it pulls — good lines put tension on weak beats and resolution on strong beats
A good melody over chords alternates between consonant chord-tone notes (scale degrees 1,3,5,7) that feel settled and tension notes (2,4,6) that pull toward resolution. The metric placement is what makes it work: tension on weak beats creates pull, resolution on strong beats releases it, giving the line directed motion rather than random in-key wandering. The source recommends, in generative contexts, constraining the melody to the scale (scale-constraint) and biasing generators toward chord tones on strong beats so consonance emerges automatically.
Examples
Over an Am chord: C (chord tone) on beat 1, D (tension, 4th) on the ‘and’, E (chord tone) on beat 3, B (tension, 9th) on the ‘and’ of 3 — strong beats resolve, weak beats pull.
Assessment
Design a 4-note phrase over Am that follows the tension-resolution principle. Mark each note as chord-tone or tension and give its metric position.