The earliest form of notation of which we have any knowledge is called the Neume notation. These Neumes were much like Greek accents in some respects, and in others resembled a sort of shorthand. All that could be accomplished by them was an indication of the direction in which the voice was to move, whether up or down, and of the number of notes which it was to pass. In Hucbald's day a series of horizontal lines, like our musical staff (but containing many more lines) was used. The names of the notes were written opposite the ends of the spaces between the lines, and then each syllable of the text was written in the space belonging to the note to which it was to be sung. Short lines were drawn upward or downward, as the case might be, between each syllable of one part so that that part could be followed. Another system in use in Hucbald's time, and even later, was arranged this way, the letters representing the tones:-- [Music: F \ D E G E / \ \ \ C D F D Lau-de dig-num ca-nat sanc-tum.] As time passed on it became evident that there ought to be some way of indicating a fixed pitch from which the notes were to start. So a line was employed and the Neumes were written in a definite manner with relation to it. If the line was red, the chant was in the key of F, and all melodies ended on F. If the line was yellow, the key was C. In the eleventh century both lines were used at the same time, and the certainty of the meaning of the Neumes became greater. Afterward Guido, of Arezzo, a famous teacher and theorist, who died in 1050, added two more lines, and thus came into existence a four-line staff. The character of the Neumes themselves had undergone many alterations, until, in Guido's time, they began to look a little like modern notes. But still there was no rhythm in the ecclesiastical music, and no way of representing it in notation. Franco advocated the introduction of measure into church music. He did not, of course, invent it, for it already existed in the popular songs and dances of the people, and had existed in them from the earliest times.