Example 34. Visualization of computing pitch permeation (for pitch D). After its initial occurrence, pitch D recurs two more times (recurrence = 2), and it is infused with five other pitches (F, B♭, C♯, G♯, and A); thus its permeation is 2 × 5 = 10, which corresponds to the area of the rectangle. (In the rectangle, upward stem notes correspond to recurrences and downward stem notes correspond to infused pitches.