In the previous post we talked about the song's melodic range. Each part of the song has its own melodic range, as well, and you can use melodic range to help define your song's structure.
There's a very conventional way to do this. The first part of the verse uses a low and narrow melodic range, often with only two or three notes. The "part B" of the verse moves to a slightly higher register. And the chorus introduces even higher notes, often including the highest notes in the song.
Using a higher melodic range for the chorus, and often also a wider melodic range, is one way to help the listener hear that the chorus the high point of the song.
In some songs, the chorus also has longer notes than the verse. The verse has more syllables to squeeze in, so the notes have to be shorter. The chorus, with fewer lyrics, spreads out with sustained notes or melismas. (A melisma is a single syllable stretched out over several melody notes.)