High Quality Content by WIKIPEDIA articles! In music, 53 equal temperament, called 53-TET, 53-EDO, or 53-ET, is the tempered scale derived by dividing the octave into 53 equal steps (equal frequency ratios). Play (help·info) Each step represents a frequency ratio of 21/53, or 22.6415 cents ( Play (help·info)), an interval sometimes called the Holdrian comma.