idea

The fifth

The fifth, ratio 3:2, is the most consonant interval after the octave. Harmonic 3 of the lower note has the same frequency as harmonic 2 of the upper one, and when the fifth is pure that shared harmonic sounds steady, without beats. This makes the fifth easy to tune by ear, and violinists tune their four strings this way. Theorists in China, Greece, India and the Arab world all used chains of fifths to build their notes.

Connects to

• Roughness and consonance
• Ratios
• The octave
• The Pythagorean comma
• Twelve notes

Sources

1. Wikipedia: Harmonic series (music)
2. Wikipedia: Shí-èr-lǜ (Chinese twelve pitches)
3. What is music? Module 6, the fifth, the easiest interval to tune and Lab 6