Analysis of the vowel/consonant patterns in a world sample of folk songs indicates that some speech sounds vary regularly with certain aspects of social structure. Consonant frequencies shift in relation to technological level: mid stops, fricatives and laterals increase in relative frequency along a scale of productive range. Alteration in the vowel map, on the other hand, seems to be related to cross-cultural differences in sex role. Thus changes in phonology, familiar to the linguist, may be symbolic of and explained by familiar societal phenomena. These suppositions are, it is true, based on the analysis of sung languages and remain to be confirmed for speech. However, the power of expressive style as a general diagnostic of the layout of culture implies that they will be so confirmed, since expressive patterns often turn out to be a sort of heightened and extra-redundant version of everyday behavior. Moreover, collections of recorded song performances provide a world-wide resource of ‘unselfconscious’ and culturally validated language data that is simply unavailable for other kinds of speech activity. (Phonology; variation; expressive (stylistic) function; song style; mode of production and se role; cross-cultural sample.)