This article proposes the practice of hexachord solmization as a component of a "histor ically informed" theory curriculum for early-music students. Many theory treatises and singing manuals from the sixteenth century and before start with a discussion of the gam ut, hexachords, the Guidonian hand, and solmization syllables. This strongly suggests that hexachord solmization was one of the principles of contemporary music education. Analyses of musical excerpts demonstrate that a hexachord is a meaningful melodic unit rather than a random set of six tones. Its solmization syllables illuminate the inherent tonal relations around the semitone mi–fa ; furthermore, they represent expressive tone qualities in themselves—for instance, the bright mi versus the soft fa. The hexachord sys tem was still in use in eighteenth-century Italy, apart from some adjustments with regard to the emerging major-minor tonality. Most likely, young apprentices at Italian conserv atories learned the syllables before they could read the pitches. Sets of solfeggi produced by the conservatory masters for their pupils show how plain solmization patterns form the basis of the melodic art of the period. In the classroom today, hexachord solmization offers both a useful tool for a non-verbal mode of musical understanding and a starting point for melodic improvisation.