epa05790152 Adele holds up her awards in the press room during the 59th annual Grammy Awards ceremony at the Staples Center in Los Angeles, California, USA, 12 February 2017. Adele won the awards Record Of The Year, Album Of The Year, Song Of The Year, Best Pop Solo Performance and Best Pop Vocal Album, with the album '25' and song 'Hello.'  EPA/MIKE NELSON
The Grammy Awards have been criticised over a lack of transparency by artists such as The Weeknd. Pictured, Adele with her five Grammys in 2017. EPA 

How do the Grammy Awards work and why are they so controversial?