Figure 3. The three genera as they are embedded in Vicentino’s 31-tone tuning, with interval names given as they appear in L’Antica musica. Each genus is shown here to scale, the visual proportions matching the size of the intervals involved. Beneath each genus appears its decomposition of the ascending perfect 4th into minor enharmonic dieses (the step-interval of the 31-note scale), summing in each case to 13 parts; beneath that are the intervals, in cents, between each of the upper notes and the A at the bottom of the tetrachord. Note that the minor semitone and the major enharmonic diesis are the same size: two minor dieses (77.419 cents).