The 'Rocket Man' singer spent two nights in intensive care after becoming "violently ill".
Prince William performs with Jon Bon Jovi and Taylor Swift at gala - video and pictures
If being a Royal doesn’t work out for Prince William, he could also try his hand at singing. Last night (November 26, 2013) he joined Jon Bon Jovi and Taylor Swift on stage for a surprise performance of 'Living On A Prayer' at a charity gala in Kensington Palace.
Watch the performance: