Pop music surrounds us, but how often do we really listen to what we’re hearing? Switched on Pop is the podcast that pulls back the curtain on pop music. Each episode, join musicologist Nate Sloan and songwriter Charlie Harding as they reveal the secret formulas that make pop songs so infectious. By figuring out how pop hits work their magic, you’ll fall in love with songs you didn’t even know you liked.

When trouble strikes in music town, there’s one guy who gets the call. That’s me, Joe Treble, forensic musicologist. This week, I've got one of the most shocking cases I've ever worked. Someone killed the key change in pop music, and I’m going to do whatever it takes to find the perpetrator.

The key change used to be at large on the Billboard charts. From the 1950s to the 1990s, 20-30% of all number one hits featured one.

In Whitney Houston's "I Wanna Dance With Somebody", the key change hits right before the final chorus. The song’s harmonic center shifts up, raising the pitch of the song, challenging the vocalist to hit higher and higher notes, juicing the big finish with excitement and pep.

But starting in the 1990s the key change virtually disappeared from the Hot 100. Now, hit songs start and end in the same key, and no one seems to have even noticed. Except for me.

This investigation will bring me face to face with a rogue's gallery of suspects and sources: Chris Dalla Riva, music and data specialist; Brandon McFarland, alias 1-O.A.K., producer; Emily King, singer and songwriter. Each interrogation brings me closer revealing the murdered, but I be able to handle the terrible truth? Tune in as I tackle the hardest case of my career: the case of the missing key change!

[audio audio="https://traffic.megaphone.fm/VMP7778161814.mp3" title="Who killed the key change in pop music?" descr=""]