The Rolling Stones have reportedly reached out to Adele, Lady Gaga,Florence Welch of Florence and the Machines and Paloma Faith to join them as special guests at London's Hyde Park next month.

The Sun quotes a source who says, "The Stones would love to get Adele on with them. It would be a massive coup, even for them, because she’s been a bit reclusive since her son Angelo James was born. She is the name they want to announce as their special guest... At the minute it's 50-50 that she’ll do it, but Mick Jagger is quietly confident he can pull it off.”

Gaga joined the Stones when they played in Newark, New Jersey last December -- she sang on "Gimme Shelter" -- and Florence Welch did the same song with them last November in London.

The Stones' 50 and Counting tour heads to Toronto on Thursday.