revert In music two octaves plus a semitone equals Dear Dicklyon I agree with you that without a RS we should not include a lot of text on this However even if I can not find a RS right now the fact can not be in dispute since it is as valid as 1 1 2 for which I would not know how to find a RS Could we not agree on including this one sentence in the disputed sightings section hoping that someone will find this knowledge useful and or will find a source for it We could attach the fact tag if you like talk