In sixteenth-century Italy, one of the chief debates among music theorists centred around the problem of tuning and its impact on the ear in performance. More specifically, the debate focused on the merits and disadvantages of untempered and tempered tuning genera, typically associated respectively with the human voice, deemed the most flexible of all musical instruments, and with other instruments made by the human hand. Vincenzo Galilei continued the tradition of partnering the genera with Nature and Art in his own music theoretical writing. Although Galilei recognized the foundational role of the diatonic genus, he was by comparison less beholden to it, ultimately arguing for greater flexibility in the application of the genera than Zarlino was prepared to admit. As Galilei will subsequently state more explicitly, Nature provides the substance and character of the voice but Art provides the form, meaning the genera.