News Flash: The majority of the music industry is shallow and appearance driven. This applies especially to women. You’ll be hard-pressed to find a successful female pop singer who doesn’t fit a particular body image or age window for most of music history, sadly. For these reasons, the story of Susan Boyle is pretty incredible.
Producers will use this technique when they have a double chorus in their hands. If the second half of that double chorus will also be the final chorus, it can be a challenge to keep the energy at peak level. And, of course, nobody wants the final chorus to be one that loses its impact or gets boring near the end.