It should be noted here that in the transcriptions of Troubadour songs--and most of the small manuscript treasure preserved to us still wants unfolding--there has until recently prevailed the error to interpret them as measured music. Measured music came into use, we have seen, with Franco of Cologne, about A. D. 1200, but, nevertheless, many writers did not adopt it for centuries thereafter. The Troubadours persistently followed the metre of the verse instead of fitting their melodies into a set rhythmic scheme (and most naturally so, when we consider that they were primarily poets); hence the square notes in which they note their melodies are really nothing but _neumes_ on a staff. This use has given rise to the error common to most historians, who, in forcing the beautiful, spontaneous tunes into a straitjacket of modern measurement, deprived them of their rhythmic and melodic grace in a manner which did violence to the verses as well. In considering their musical quality we must call attention to the fact that, while devoid of the rich beauties of modern harmony, these songs, availing themselves both of the antique modes and modern tonalities, are able to convey nobility of sentiment, passion, and varied shades of emotion. Breathing the 'tender grace of a day that is dead,’ they are, in some instances, still able to charm in our noisy age, and the influence which they have had upon the course of the art can hardly be over-appreciated. It has been mentioned that the Jongleurs came largely into the service of the Troubadours. It is they who accompanied the knights in their travels from castle to castle, providing the lighter kinds of amusement, and the instrumental accompaniment, such as it was, on their viols or rottas--sometimes, indeed, singing their master’s songs, with the dissemination of which they were frequently entrusted. That they often undertook to 'improve’ these compositions on their own account we gather from the words of Peire d’Auvergne and others, entreating jongleurs not to meddle with their verses and melodies. Sometimes, no doubt, they were more gifted than the Troubadour and provided the melody for his verses as well. In some instances, indeed, a Jongleur became a Troubadour or Trouvère, and sometimes a Troubadour became a Jongleur, as in the case of Gaucelm Faidit, who lost money at dice and was forced to earn a livelihood by his art. For that was the real distinction between the two; one sang for glory, the other for gain. As long as they did not make a trade of their art, lowly-born and bastards took equal rank with princes and nobles, in the earlier periods at least.