Easy as hey, B, C: how this euphoric yell took over pop music

The abrupt utterance has infiltrated the charts, from Katy Perry to the Weeknd, in the past two years. Is it an industry joke or simply a way to fill space in a song?In the weekly pop steeplechase of the Top 40 a sudden, percussive shout of “Hey!” is the stuff of thoroughbred chart champions. Consider the biggest tunes of the last few years and your playlist will sound more like a “heylist”. “Hey!” has been part of pop for decades, but in 2013 Katy Perry&rsquo