How Shazam spotted a No. 1 Billboard song before it was even a hit

Remember "All About That Bass"? The single, by Meghan Trainor, topped the Billboard Hot 100 and was heard around the world.

But it wasn't radio play that made "All About That Bass" famous. We can use charts from music app Shazam and others to examine exactly how it went viral - and to see how Shazam can predict which songs are going to be hits before they're even at the top of the charts.

Here's a chart that Shazam has been handing out at Mobile World Congress in Barcelona. It shows the UK Shazam searches, sales, and radio play for "All About That Bass":

Shazam is an app that people can use to identify music they hear. Fire up the app, hit the Shazam icon, and it records what you're hearing and tells you what song is playing.

People heard "All About That Bass," didn't recognize it, and used Shazam to find out what it was. That preceded the sales peak. And radio play was way behind - it took months for stations to start playing the song on rotation.

Here's another chart that shows the US reaction to "All About That Bass":

Again, Shazam picked up "All About That Bass" first. But this chart shows Spotify plays - and they're the third peak, after sales.

Shazam also measures where searches are coming from. Here's a chart that shows how it spread in the UK:

So if you want to know what the next song is, Shazam's data can tell you. Thankfully, the data isn't private. Shazam publishes it on its website: