Top artists and songs of the 2000s (By sales and awards)

It's officially the time of year when Spotify and Apple Music provide data on what songs, artists, and albums are most popular and which ones each user listens to most. But it wasn't always that easy to know what music people were listening to.

CNN Money called the 2000s "music's lost decade," because the music industry took major hits—and information about the industry did too. Thanks to the recession and the rise of music piracy, the number of people purchasing music dropped drastically, making it hard to know what people liked most.

There were four main genres of music that were thriving in the United States during the 2000s. Continuing on from the boom in the 1990s, pop music was very popular. This was aided by music competition shows like American Idol, which helped push out new, mainstream stars. Country music also saw a considerable rise in popularity and recognition during this time.

While pop and country seemed to be most dominant in the public eye, there were two music genres that had massive fanbases, yet relatively little coverage. These were hip hop, which had been building popularity in the previous two decades, and emo music. Access to personalized music on mp3 players and the newly-introduced iPod allowed non-mainstream music to gain a considerably higher following than it might have in other time periods.

Because of that, the top songs of the decade are contentious. By some metrics, it seems like the 2000s were all about hip hop and rap. By others, it seems like the country-pop realm was dominating the industry.

Click to the next slide, where we discuss the top music according to album sales.