Florence Welch told Dave Grohl to eat broccoli to heal his broken leg.
The Florence + the Machine singer - who broke her foot jumping off stage at Coachella earlier this year - sought advice on calming her nerves ahead of headlining Glastonbury, a gig she was given after the Foo Fighters frontman's injury caused his group to pull out, and in return offered some health tips.
She wrote: "I'm so sorry you broke your leg. I know how that must feel. I broke my foot onstage too only a few weeks ago. What idiots we are!
"But let me recommend eating lots of broccoli as it aids the healing process. It's the iron.
"If you in turn could recommend something that would quell my outrageous nerves, that would be lovely."
In response, Dave wrote back and suggested Florence watch a performance of Freddie Mercury performing with Queen at Live Aid in 1985, insisting it was the right way to play on stage.
Florence noted: "So sweet. And so true! That really is how you do it."
The 'Spectrum' singer found one of the best ways she could prepare for the gig was to visualise it in her mind.
She admitted to Q magazine: "I played Imaginary Glastonbury about 17 hundred times. That helped.
"Rod [Ackroyd, guitarist] spent a lot of the time watching old Oasis at Glastonbury videos. Or maybe it was Blue. Always get those guys mixed up."