As time has evolved, more musical instruments have developed resulting in more sophisticated and complex sounds being produced. The rhythm, pitch and lyrical content of songs have all changed along with the changes in culture over time. To help analyze these changes we use Spotify's and Billboard's Top 100 data (gathered from Kevin Schaich) . Spotify is a digital music service that gives users access to millions of songs, podcasts and videos from artists all over the world.¹ Consequently, Billboard Top 100 is the music industry's standard record chart in the United States for songs. Chart rankings are based on sales (physical and digital), radio play, and online streaming in the United States. A new chart is compiled and officially released to the public every Tuesday.² As a result, we can analyze songs from 1980 to 2015 by comparing their tempo (pace of music), loudness (the overall volume of a recorded song), energy (the perception of intensity and activity), as well as many other attributes for specific years since 1980.

Users can interactively choose a year they are interested in to get a closer look at details to help answer questions such as:

-How has popularity, danceability, and energy in music changed from 1980 to 2015?

-How has loudness, valence, and tempo in music changed from 1980 to 2015?

-What caused these changes?

-How are these changes reflected in the music?