If you follow dance pop, the speed at which a song moves from new to used is stunning.The Black Eyed Peas "The Time" was a disaster so fast they couldn't see it coming: it didn't hit and disappeared in the blink of an eye. As did Lady Gaga's "Judas", Britney Spears "Hold It Against Me", Beyonce's "Run This World (Girls)".
the thing is, the flip side of dance pop, is that it hooks through rhythms and not melody.
This is a sea change over a decade in arriving. The harbinger was, of course, James brown, who excelled at rhythmic hooks, but the pop explosion of the 2010's has lead straight to the state of the charts.
the question is this: though you can speak a lyric hook, you can't sing a drum pattern, so it doesn't embed itself as hard into your memory. That's why P. Diddy's invention (indeed, inversion) of the sample is so important. Look at it this way:
1. Rap started by scratching and repeating rhythms on vinyl on turntables (by James Brown for one) and rhyming to the beat.
2. Diddy sampled songs chorus ("Mo Money, Mo Problems" is the perfect example) and the rapper rhymed in the spaces.
3. As dance and hip hop evolved together though,the most popular musicians inverted it again, they got rid of the raps.
The result was a reliance on beats as hooks which, if the melody wasn't there, was all that could be held to. The songs can be too easy to forget. They disappear as if they'd never existed