My initial thoughts were that they are all dead, but as you mentioned, Elton is still alive. XXXTentacion and Tupac were murdered but Buddy Holly was killed in a plane crash. But maybe the link is death as Elton sang at the funeral of Princess Diana.
I have picked this post on behalf of the @OurPick project which will be highlighted in the next post! 
RE: πΊππππ π»ππ π΄ππππππ πΉππ π ππ & πππ π $1 πππππ - [#TTT Week 14] - "X Marks the Spot"