497.INTRODUCING A SECONG PARALLEL SIMPLER AND SLOWER LAYER OF HARMONY BELOW THE CHORD PROGRESSION, FROM ONLY 3 ANCIENT (POWER) CHORDS WITHOUT INTERVALS OF THIRDS SO AS TO IMPTOVE THE STABILITY AND QUALITY OF ARRANGEMENT .

 INTRODUCING A SECONG PARALLEL  SIMPLER AND SLOWER LAYER OF HARMONY BELOW THE CHORD PROGRESSION, FROM ONLY 3 ANCIENT (POWER) CHORDS WITHOUT INTERVALS OF THIRDS SO AS TO IMPTOVE THE STABILITY AND QUALITY OF ARRANGEMENT .