We propose a way of looking at phonological typology that is based on a fundamental distinction between a phonetic and phonological analysis of the sound systems of languages. We build on approaches to phonology pioneered by Sapir and the Prague School (Jakobson and Trubetzkoy), instantiated within a generative grammar. We view phonemes as being composed of contrastive features that are themselves organized into language-particular hierarchies. We propose that these contrastive feature hierarchies shed light on synchronic and diachronic phonological patterns, and therefore offer a new lens on phonological typology. Thus, on this view the subject matter for typological investigation is not a phonetic sound (e.g., [i]) or a phoneme (/i/), or even a phonemic inventory (/i, a, u/), but an inventory generated by a feature hierarchy: for example, /i, a, u/ generated by the hierarchy [low] > [round]. This yields a different set of representations from the same terminal symbols generated by the hierarchy [round] > [low]. We will illustrate this approach to phonological representations with a synchronic analysis of Classical Manchu, and then show how it accounts for the results of typological surveys of rounding harmony in Manchu-Tungusic, Eastern Mongolian, and Turkic, and for the distribution of palatalization in Yupik-Inuit dialects. We will then propose that contrast shift should be recognized as a type of phonological change, and show how it applies to diachronic developments of the Algonquian and Ob-Ugric vowel systems. We find that feature hierarchies can be relatively stable, but contrast shifts do occur, for various reasons, and these can result in dramatic differences in patterning. Harvey’s analysis of Ob-Ugric also shows that elements of feature hierarchies can spread and be borrowed, like other aspects of linguistic structure. As Sapir (1925) proposed, languages whose phonemes line up in similar ways (i.e., have similar contrastive feature hierarchies) show similar phonological patterning, though they may differ considerably in their phonetic realizations. We conclude that contrastive feature hierarchies provide an interesting level of representation for typological research.