Coldplay wowed the crowd at Glastonbury, leaving no question about their status as one of the world's best bands.
But some of Chris Martin's fans did have a question after their performance - what was up with that piano?
The rocker was sat playing the instrument towards the opening of their set and many viewers noticed his unusual rocking motion as he tinkled the keys.
-- Justin Aylett (@Juzzy_Aylett) June 26, 2016
-- FrankTheTank (@FrankBergin) June 26, 2016
#ColdplayGlastonbury What is Chris Martin doing on his piano stool - I had to look away out of embarrassment (for him)
-- Paul Hershie (@ratbag36) June 26, 2016
-- Allan Reddy (@allan1234) June 26, 2016
-- Rosie Kelly (@rosemary_kelly_) June 26, 2016
Chris Martin was showing that piano way too much love #ColdplayGlastonbury
-- Hannah (@travelstarling) June 26, 2016
Chris Martin is riding that piano stool like there's no tomorrow
-- james shields (@jamshields) June 26, 2016
Why does Chris Martin keep humping his piano stool, even my mums commented on his shenanigans
-- Lucy Bailey (@LucyBailey2) June 26, 2016
-- Jon Smith (@jozzathejoz) June 26, 2016
However, that question might have been answered when Chris launched into Everglow from new album A Head Full Of Dreams, and quickly discovered there was a technical hitch.
He said: "What's going on, man? One of us is really out of tune."
After stopping the song to discuss the issue with the rest of his band, he said: "That's a terrible problem live at Glastonbury, shall we skip to the next song?"
He then decided to continue the song alone, explaining: "I can do it. Having introduced the rest of the best band in my lifetime, they've left me on my own.
"There's something wrong with the piano but we can muster through."
Maybe that was it then?