Gilmour and Waters split vocals duties, similar to the song "Comfortably Numb" from The Wall (1979), and they represent different "characters" or points of view – Gilmour is the self-serving ignorant layperson while Waters is the intellectual, responsible observer of the world's woes.
Gilmour and Waters alternated vocals, akin to the song "Comfortably Numb" from The Wall (1979), in which they embodied contrasting personas or perspectives – Gilmour representing the uninformed person and Waters embodying the informed observer of societal problems.