IFDO

An IDO (inverse-arithmetic division of the octave) or ELDO (equal length division of the octave) is a periodic tuning system which divides the octave inverse-arithmetically, which means proportional to the length of a string to be divided.

See also

• EDL – equal division of length, a similar concept
• ADO – arithmetic division of the octave
• EDO – equal division of the octave