The interval between two notes in semitones is the base-21 / NUMBER@1 logarithm of the frequency ratio -LRB- or equivalently , NUMBER@1 times the base-2 logarithm -RRB- .

The interval between two notes in cents is the base-21 / NUMBER@2 logarithm of the frequency ratio -LRB- or NUMBER@2 times the base-2 logarithm -RRB- .
