Example 21. This example compares tonal prolongation and pitch permeation in outer voices. Both are indicated with dashed slurs (blue for tonal prolongation and green for pitch permeation). (a) Blue noteheads are prolonged by red ones, which in this case are neighbor tones. (b) Green noteheads permeate; they are infused by the orange noteheads, because the orange noteheads are sandwiched between occurences of the green noteheads.