This paper provides an account of how certain instances of “headedness” in segmental phonology may be derived within the Onset Prominence (OP) representational framework. It is shown that headedness is not a primitive property of OP representation, but rather emerges directly from the phonetic anatomy of the OP representational primitives, envisioned in terms of Traunmüller’s Modulation Theory. The phonological status of voicing, including the relationship between nasals and voiced stops has been ascribed to headedness. Here it is shown to fall out from the Modulation perspective on laryngeal phonology. With regard to vowel quality, it is shown that apparent headedness effects derive from asymmetries in the modulatory properties of formant convergences as opposed to individual formants. Empirical implications of this perspective are reflected in vowel harmony patterns, by which rounding is typically less likely to be harmonic than palatality or tongue root advancement.