As modal tradition in 17th-century Italy persisted alongside burgeoning tonal theories of polyphonic pitch space the practice of solmization was continually adapted. Modality did not become tonality over time; rather, both traditions evolved in parallel as their domains of applicability diverged. I explore this moment at the dawn of a European common practice by focusing on issues particular to Adriano Banchieri's solmization and harmonization of semitones, which since antiquity have held a place of special prominence in theories of pitch space.

After reviewing Guidonian hexachords, Banchieri's Cartella musicale (1614) develops a new heptachordal system that obviates mutation by capturing all recta semitones under one system. I bring these systems into dialogue with Banchieri's resolution of semitones in his nascent thoroughbass method. The clash of theory and practice in emerging Italian tonality produce systems that I call "moveable-ut," "fixed-ut," and "tonic-ut."