You’re narrating A Christmas Carol – Unplugged. What’s that about?
It’s a stripped-back-to-the-bones show – the Scrooge story set in the music business. It has acoustic music, interspersed with me narrating Dickens’ classic. We want it to feel as if we are all in the living room together as mates, and I’m the storyteller.

How do you feel about writing the nation’s favourite Christmas song, Merry Christmas Everybody?
I’m really proud of it. We knew we had a hit on out hands when we wrote it [in 1973]. It went to number one the week of release and stayed there for six weeks, which was into the New Year. We didn’t think for a minute it would still be going strong 40 years later. It’s great that a new generation discovers it year after year. I get little kids coming up to me saying they performed the song in their school Christmas concert. Though people do forget we had 40 other hit singles, too.

Are you proud to be the third person on the Birmingham Walk of Stars?
Yeah, a mate of mine, Ozzy Osbourne, was the first person on it, then Jasper Carrot was asked, and I was voted third. It was a big honour. The ceremony was two weeks before Christmas in 2007 and 27,000 people turned up, which was phenomenal.

You’ve advertised Nobby’s Nuts – what’s the strangest product you’ve been asked to promote?
Only last week I spearheaded ‘Britain’s Sausage Week’. We went around the whole country finding Britain’s best bangers, tasting 20 sausage recipes a day!

Do you have any advice for young bands these days?
Yes: get a good accountant and a good lawyer.

Ever tempted to do a Slade reunion?
Not really. We’ve been apart for nearly twenty years and are not the same four people. We worked together in each other’s pockets for 25 years which is a long time. It was like having three marriages!

When did you know that you wanted to be in a band?
I was singing in working men’s clubs from the age of seven. The first time I sang, I brought the house down with applause. I formed my first band in school when I was 12, played the clubs in Germany like The Beatles, and then I met the guys that became Slade. I’d been playing in bands for 10 years before I had any success.

What would you have been if you weren’t in a band?
A history teacher. I was doing very well at school and the teachers were mad when I left – in those days, it was unheard of to want to be a professional musician. It was seen as the lowest of the low.

What do you think of X Factor?
They [contestants] are chasing fame more than music. It’s a great show but it is doing nothing to forward the course of music. There hasn’t been any kind of long-lasting star to come out with songs that people remember for 20 years – no one writes their own material anymore.

Mark Kermode described your film, Slade In Flame, as the “Citizen Kane of rock musicals”, but it wasn’t a success at the time …
No, it didn’t work very well for our career. People expected a silly, slapstick, Hard Day’s Night sort of thing – not a hard-hitting behind-the-scenes look at rock music. They had this image in their heads of Slade the band and they couldn’t separate it from the movie. But now it’s a classic.

If you could play with anyone from rock, past or present, who would it be?
Little Richard. He was my first inspiration in rock and roll; he made the hairs on the back of my neck stand up. No one in the UK had ever seen a black guy with his pompadour hair playing the piano standing up.

What’s your favourite Christmas song?
Mariah Carey’s All I Want for Christmas Is You. It sounds like old Fifties Motown to me – very uplifting. It is easy to write sad songs but 10 times more difficult to write optimistic songs.

You were on the BBC’s Grumpy Old Men – what makes you grumpy?
Not a lot, really. I did one series of the show and they didn’t want me anymore because they said I wasn’t grumpy enough!

A Christmas Carol – Unplugged, narrated by Noddy Holder, is on this Wednesday, Dec 14m, at Union Chapel Theatre.

Tickets £17.50,