Karl Schuster

Karl Johan Schuster (Swedish pronunciation: [ˈjûːan ˈɧʏ̌sːtɛr]; born 1 February 1985), known professionally as Shellback, is a Swedish record producer and songwriter. He was listed as the No. 1 producer of 2012 on Billboard magazine's year end chart, and he also topped the list of their "Top 10 Songwriters Airplay Chart" the same year; he has won four Grammy Awards. Shellback initially started his career as a heavy metal guitarist before transitioning into pop music production and songwriting. S…