In France the Guidonian system was adhered to closely, and to this day the _becarre_ is used only as an accidental, to indicate that the note to which it refers has been flatted before. The _naturel_ (which has the same shape) is used to designate a note that is natural to the key; thus the distinction is made between an accidental and a note that is common to the key. In F major, for instance, B[natural] is _si becarre_, A[natural] would be _la naturel_. Our modern sharp is merely another form of the natural or square B ([natural]) which gradually came to be used before _any_ note, signifying that it was raised or sharped a half-tone; the flat lowered it a semitone, and after a while the natural received its present place between the sharp and flat. The first instance we have of the sharp being used is in the thirteenth century, when (in the Rondels of Adam de la Hale) it takes the form of a cross [x] (the German word for the sharp still remains _kreuz_). The French word _diese_ (sharp) comes from the Greek _diesis_, a term used to indicate the raising of the voice in the chromatic scale. And now we have to speak of notation and its development. Thus far we have found only two ways in which musical sounds were indicated by the ancients. First, we remember the invention of Aristophanes of Alexandria, his accents, high, low, and circumflex. Then we know from Ptolemy, Boethius, and Alypius that letters were used to designate the different tones; but as there is no music extant in this notation to prove the theory, we need not trouble ourselves with it. The system of Aristophanes, however, was destined to become the nucleus from which our modern notation sprang. We know that an elementary idea, clearly expressed, has more chances of living than has a more complicated system, however ingenious the latter may be. Now this system is so plain that we will find it is common to many aboriginal peoples, for instance the American Indians have a system very similar.