It is supposed in China that Ling-Lenu, minister of the Emperor Honang-Ty, chosen to fix the laws of musical sound, retired to a bamboo-grove, near the source of the Yellow River, and there cut twelve bamboo tubes whose varying lengths yielded the sounds of our present-day chromatic scale. In reality, however, the pentatonic scale [Illustration: score] is used. The tones b and e (omitted in this scale as we have written it), the fourth and seventh tones in our scale, which are not found in the normal pentatonic scale, are given a special name, _pien_; and the union of the five tones and the two _pien_ constitute what the Chinese call the 'Seven Principles’ in music. But the five-tone scale is the one commonly employed in practice and constitutes the basis of all music in the Indo-Chinese countries.[14] In Java, Siam, Burmah, and Cambodia, both five-tone and seven-tone (heptatonic) scales are in use; but the musical system of Japan, which was originally borrowed from China, is built up wholly on a five-tone scale, with the important difference from the Chinese that it has a minor third, and not a major: [Illustration: score]. This difference gives Japanese music a certain individual character of its own. The Hindoos have a system of seven-toned scales differentiated from each other by variable quarter-tone steps. But the theory of music is developed in India with an over-elaboration of subtleties, as it is in China, and of almost a thousand varieties of scale theoretically possible in the Hindoo system no more than twenty are in actual use. Many of these resemble our own. What may be called Mohammedan music is a complex type. It has resulted from the spread of Mohammedanism along the Mediterranean coast and Northern Africa, and in Central Africa and Southern Asia. It includes features from many sources--Persian, Byzantine Greek, Mediæval Christian, and purely local--and is historically a puzzle. Like the Hindoo scales, the scales which are used in distinctly Mohammedan countries are heptatonic; but the theoretical division of the octave is into seventeen steps (each equal to about one-third of a whole step) instead of the twenty-two _srutis_ of the Hindoos. There are some eighteen of these seven-tone scales in use, varying from each other in the location of their shorter steps.