Musical Mathematical Ratios and the Engineering of Consciousness – Alexandre Tannous – Free Your Mind Conference 3 (2015-04)

Half-step has 100 cents.

Western octave is 12 half-steps (tones, notes: C, C#, D, etc. Black and white keys on keyboard)

Indian octave has 22 tones

Persian and Arabic octave has 24 tones

Turkish octave has 53 steps