Elton's latest Instagram post contains a photo of himself with Kiki Dee.
The caption says: ''Guess who showed up at my Peterborough gig?''
Incidentally, 41 years ago this month, both performers released Don't Go Breaking My Heart.
This was Elton's first number 1 hit in the UK, topping the charts for six weeks. In the US, it was his sixth number 1 hit and lasted four weeks at the top.
The song was written by Bernie Taupin and Elton, using the aliases Ann Orson and Carte Blanche.