1746: Dominical Letters and Music Sep 25, 2019

Musical notes are written in a scale denoted with letters A-G, but this could have been with numbers, or tonic sol-fa (do, re, mi...). Indeed, many other systems have been used through history. Given that other terms like 'octave', 'third' and 'fifth', now for music originated for calendars, it may not be surprising that the most popular, now-ubiquitous system was one from the calendar. Letters used to denote with which day of an 8-day week a year or month started was already in use, called dominical letters, so the pattern would have already been familiar to many.