Complex sentence: Division of the octave into 19 steps arose naturally out of Renaissance music theory: the greater diesis, the ratio of four minor thirds to an octave (648:625 or 62.565 cents) was almost exactly a 19th of an octave.
Split into simpler sentences: Division of the octave into 19 steps arose naturally out of Renaissance music theory. The greater diesis, the ratio of four minor thirds to an octave (648:625 or 62.565 cents) was almost exactly a 19th of an octave.