Mutations

A 2 2/3' stop sounds the pitch one octave and a perfect fifth above the key being played. A perfect fifth equals seven half steps, not including the bottom key but including the top. A perfect fifth up from C is: C#, D, D#, E, F, F#, G (seven half-steps).

This is the twelfth, the third partial or harmonic, and the second overtone.

2 2/3' stops are referred to as fifth-sounding stops. Fifth-sounding stops sound the note name at some fifth above the key being played (one or two octaves plus a fifth).

To locate the sounding pitch:

• Pull a 2 2/3' stop only and play tenor C. Remember this pitch in your head.
• To locate the actual sounding pitch: cancel the 2 2/3' stop, pull an 8' stop, and play the key an octave and a perfect fifth above, two G's above tenor C.
• This pitch should match the one you heard when you played tenor C with only a 2 2/3' stop pulled.