Avicii was one of the most popular EDM acts of the past few years, and consistently appeared on lists of the highest-paid DJs in music. He had multiple huge EDM hits, including "Levels," "Wake Me Up," "The Nights," "Waiting for Love," "Hey Brother," and "Sky Full of Stars" with Coldplay.
28 is far too young to go, damn. I can't say I was a huge fan of his music, but he brought so much joy to millions of people. There's nothing like a dancefloor when "Levels" starts up.
Rest in peace.