Swedish record producer, songwriter, and multi-instrumentalist. Shellback 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. He regularly collaborates with songwriter Max Martin, and together they have produced, written, or co-written songs for P!nk, Taylor Swift, Adam Lambert, Britney Spears, Usher, Avril Lavigne, Ariana Grande, Adele, and Maroon 5. Shellback has also collaborated with fellow pro…