The Harmonic Series

1 1/3' PITCH (the sixth partial)

As the string continues to vibrate in this complex way, it also vibrates in sixths, producing the nineteenth, the G two octaves and a perfect fifth above tenor C. This is the sixth partial or harmonic, and the fifth overtone.

If you were to play tenor C at the organ and pull a 1 1/3-foot stop only, you would hear the nineteenth, the G two octaves and a perfect fifth above tenor C.

1 1/3' stops are fifth-sounding stops, which sound the note name a fifth above the key being played.

HINT: 1 1/3 is half of 2 2/3, resulting in a pitch one octave higher than 2 2/3' stops. They share the same relationship as do 4' and 8' stops; that is, they are an octave apart. This helps to distinguish 1 1/3' stops from 1 3/5' stops.