‘Tone’, at least in the literature dealing with Far Eastern languages, is commonly used in several ways: for instance, in ‘the tones of the language’, or ‘Cantonese has seven tones’, reference is made to the tones as membersof a system, while in ‘such-and-such a word has tone X’ the reference is tothe assignment of an item to one of the members of the system. The differencein reference is made quite clear by the context, and no ambiguity ensues; theconcept of ‘tone’ remains precise, and difficulties arise only when no distinctionis made between ‘tone’ as used above and the realization of tones in particularenvironments. Far different is the use of expressions denoting ‘changes intone’, for which there is no agreed terminology. In diachronic work, ‘change’ usually refers to changes through time in the overall system of basic tones, and secondarily to changes in the assignment of items to members of this system, as, for instance, when it is said that in Standard Chinese, items with voicedplosive initials changed from the shăng tone to the qù tone by the Sung dynasty.