Michael Eavis is famous for having founded the Glastonbury festival. He is 75 years of age now but still active in organising the event. When asked about his memories in June 2011 he comes up with a surprising favourite act. We quote from the website This Is Somerset:

Virtually every major rock act has played Worthy Farm, apart from the Rolling Stones, and Mr Eavis is confident of booking them one day. But few would guess his personal favourite was the late John Martyn, the singer-songwriter who played in 1979.
"He was so good, it brought tears to my eyes. The world would not think that was the major thing at the festival, but to me it was. Then there were The Smiths, Oasis and Radiohead. And T-Rex, who replaced The Kinks at the first festival, was one of the best ever."

Good to read this and thanx to John Neil Munro who discovered it.

July 2015 Eavis added some comments in another interview on the website High Profiles.

Who have you had and it's been like a dream come true?
John Martyn [in 1979] was one of the best moments.

Was he a big hero of yours?
Well, I wouldn't… I didn't like him as a person. He used to drink a lot and he was always difficult. He said, 'Why don't you treat me like a rock star?' and I said, 'You're not a rock star. Sorry! You're a very good folk singer.' He was a bit of a nightmare, really. But he was brilliant. His music was really, really moving. Really moving.

June 2017 Michael was milder in a Q&A for Somerset Live.

A young lad asked what is the nicest band that ever played Glastonbury?
"The nicest person that did play was John Martyn. He played in 1979, it was a few weeks before Emily was born."

In the book Glastonbury 50 (2019), co-written with his wife Emily, Michael reminisces about the 1979 edition:

It was a marvellous event. The weather was nice -I dread to think what would have happened if it hadn't been– and the bands were great. John Martyn's set that year was one of my best Glastonbury moments. Twelve thousand people showed up. It was a huge success.

And a recent quote (June 2021) from an interview about Land Rovers:

You say in your book that John Martyn's 1979 set that year was one of your best ever Glastonbury moments. What makes a great Glastonbury moment?
Yeah, I enjoyed his stuff at that time. That set in 1979 just captured the moment for me, really. It was absolutely brilliant. There are things every year that stand out, though. It goes on and on, and we're not finished yet!