He's a hero of British folk and his stroll through the Streets Of London has passed into songwriting legend. But will he walk away from the 10 questions we ask everyone?
What was your first guitar and when did you get it?
"I bought it in Kennard's department store in Croydon. It was an impossible beast of torture made of plywood with a fishtail and untunable machineheads made by Egmond Freres in Belgium.
"It cost five guineas and I was robbed. It lay dormant in the council flat until my mum sent it to me while I was in the Army at Shropshire. It haunts me still."
The building's burning down, what one guitar would you save?
My temporary quitting was a sincere attempt to regain my musical integrity and I have no regrets whatsoever
"My Gibson J-45 that I have had since I was 20 years old. I traded it in against a Harmony 12-string and £45 at Pan Music on Wardour Street. It was the best trade-in I ever had, and my hand and fingers grew round that instrument.
"90 per cent of all my writing has been done with that guitar and, although I rested it for several years, it will be with me till the drop. I now have at least six more J-45s and only one of them gets close to this beloved guitar.
"My guitar is called Miss Gibson after the Reverend Gary Davis's J-200 Gibson, which he favoured most of his playing life. I now have a J-200 as well, just like the great man."
What's the oldest guitar that you own?
"I have a 1920s archtop Gibson L-1 that has a round soundhole, and doesn't have much volume. I just wanted to own this particular classic. I also have a 1932 000-28 Martin that I bought off a guy in 1961 after he heard me playing outside a pub called The Angel in Poole, Dorset. He acquired it from a bloke who said it was owned by the guitarist in the original Billy Cotton Band."
What plectrums do you use?
"I mostly play fingerstyle, but occasionally, I'll use light-tomedium plectrums."
When was the last time you practised and what was it?
"I play every day. I seldom practise… I never tire of working on the wondrous technique of Reverend Gary Davis and Blind Arthur Blake. I have made an instrumental album called Sofa Noodling which is basically what I do when I'm playing guitar on my sofa."
When was the last time you changed your own strings?
"I am the only one allowed to change my strings and I change them for every gig. I was shown a great way to tie strings by Jerry Donahue. He called it the 'Nashville tie'.
"I showed it to an Aussie musician, and he has shown it to several other Aussie musicians and tells me it is known as the 'McTell tie' over there. It is seldom that anyone could boast that one had shown Bert Jansch anything to do with acoustic guitar, but I showed him this method, and he showed me a way of quickly unwrapping guitar strings. I change mine every gig, therefore I think about my dear friend Bert every time I go to work."
If you could change one thing about a recording you've been on, what would it be and why?
"I would remove three songs from my first album, because I was made to record them for the sake of my publishers and I had no idea what they were about. One of them was Suzanne by Leonard Cohen – I still don't know what it's about!"
What are you doing five minutes before you go on stage and five minutes after?
"Before: pacing and checking my pulse. Picking up song lists, constantly checking I have all my spare capos, water, shirt buttons, picks, and so on. Then I do it all over again.
I never went into music as a career. The career happened because of music
"Fix my in-ear monitors, check I am getting signal from the desk. Check everything again. Wonder if I will remember the words to a newly included song. After: wait until my skin changes colour, and go out to meet and greet the lovely people."
What song would you play on acoustic around a campfire?
"I wouldn't, but I would like to have still had my Egmond Freres guitar, which I could then throw on to the flames."
What's the closest you've come to quitting music?
"After Streets Of London was a hit in 1975 to '76, there was too much pressure to repeat the success that came accidentally, and was not the course I would have chosen. I never went into music as a career. The career happened because of music.
"I realise how lucky I've been and how my life was altered forever because of the success of Streets, but I regard it as a blip on my graph and I know I've written better songs and am still trying to improve on what I've already done.
"My temporary quitting was a sincere attempt to regain my musical integrity and I have no regrets whatsoever. I did take some talking into doing Alphabet Zoo and Tickle On The Tum. But, truthfully, I have no regrets doing that either… There is now a third generation growing up with Kenny The Kangaroo."
Ralph McTell will play the Royal Albert Hall in May 2016