Diapason

Diapason (Latin diapason ) is originally the Greek name for the octave. Ancient Greek διαπασων Diapason is composed of διά dia and πασων [ χορδων ] Pason [ chordōn ], which means " through all the [ notes ] ."

Because the octave is produced by shortening the string or pipe lengths, towards the French, the word diapason the musical instruments and in another relationship even with the mood of the instruments, so that Diapason can mean not only scale, but also pitch and tuning fork.

Diapason further referred to an organ stop.