Meet the bald Norwegians and other unknowns who actually create the songs that top the charts.  
An excerpt from THIS article: http://www.theatlantic.com/magazine/archive/2015/10/hit-charade/403192/

Most Americans will recognize their songs, however. As I write this, at the height of summer, the No. 1 position on the Billboard pop chart is occupied by a Max Martin creation, “Bad Blood” (performed by Taylor Swift featuring Kendrick Lamar). No. 3, “Hey Mama” (David Guetta featuring Nicki Minaj), is an Ester Dean production; No. 5, “Worth It” (Fifth Harmony featuring Kid Ink), was written by Stargate; No. 7, “Can’t Feel My Face” (The Weeknd), is Martin again; No. 16, “The Night Is Still Young” (Minaj), is Dr. Luke and Ester Dean. And so on. If you flip on the radio, odds are that you will hear one of their songs. If you are reading this in an airport, a mall, a doctor’s office, or a hotel lobby, you are likely listening to one of their songs right now. This is not an aberration. The same would have been true at any time in the past decade. Before writing most of Taylor Swift’s newest album, Max Martin wrote No. 1 hits for Britney Spears, ’NSync, Pink, Kelly Clarkson, Maroon 5, and Katy Perry.

Read the entire piece here: http://www.theatlantic.com/magazine/archive/2015/10/hit-charade/403192/