Reliable data on tone systems has been assembled through a survey of a large sample of tone languages. Simple two‐tone systems are the most frequent; added tones reduce the frequency of occurrence. While two‐ and three‐tone systems generally have only level tones, both level and contour tones are commonly included in four‐tone systems. Five‐tone systems generally include level, rising and falling tones, while contours that move in the same direction but differ in the amount of pitch change are typically found only in large tone inventories. Thus, the commonest inventories exploit only contrasts of pitch level, larger inventories add contrasts on a dimension of direction of movement, and only the most elaborate and least common inventories are likely to use contrasts of amount of change. These dimensions correspond in ranking with the cognate perceptual dimensions ofaverage pitch, direction, andslopefound by Gandour and Harshman [Lang. Speech21, 1–33 (1978)]. Here the ranking implies, roughly, that subjects relied most on the average pitch dimension to discriminate between tones, then next they relied on the direction dimension, and so on. The correspondence between the two rankings suggests that tone inventories are elaborated by recruiting progressively less salient perceptual dimensions.