equi-tonal system

The term "equi-tonal system" in music refers to tuning systems based on the principle of equal intervals. While Western music commonly uses the chromatic scale, which divides the octave into 12 equal semitones (equi-dodecatonic), African musical traditions feature equi-pentatonic (five notes per octave) and equi-heptatonic (seven notes per octave) systems. These systems, though theoretically based on equal steps, often involve approximations in practice, sometimes accommodating consonant intervals like fourths and fifths. This contrasts with Western equal temperament, where the octave is divided into 12 equal semitones, allowing instruments to play in all keys with minimal intonation flaws.12