When the BBC asked if I’d become involved in the Comic Relief extravaganza, obviously my initial reaction was “no”. I saw no reason to give up my time so a couple of African dictators could buy bigger Mercs.

But then I was told the Comic Relief money doesn’t actually buy cars or bigger power tools with which Mr Mugabe can drill into his opponents’ heads. It buys useful stuff such as ambulances and help for the mentally ill of Britain.

And anyway, saying no to the Comic Relief team is a bit like saying no to the man at the Tube station with the stack of Big Issues. In fact it’s even harder because you can’t smile and say: “It’s all right, I’ve already got one.”

So what did they want me to do? Wear a leotard and flail about on an ice rink? Sing? Stand in a school playground while children rubbed lumps of elephant dung into my hair?

It turned out the offer was even worse. Would the three Top Gear presenters like to appear on a humorous celebrity version of A Question of Sport?

As I’d rather have spent the afternoon sitting on a ham slicer, I came up with another idea. What about Top Gear of the Pops? It’d be like Top Gear, only instead of cars we’d have music. And then, I said jovially, we could finish with a tune from the Top Gear band.

The Comic Relief people loved this, and commissioned it immediately. And that was great, except for one teeny weeny detail. There was no such thing as the band.

Yes, Richard Hammond used to play bass with a band 20 years ago but gave up when, in a fit of temper, he broke his guitar over the singer’s head. And sure, James May is an accomplished harpsichord player with a degree in the science of music. But while he’d be good at Brahms and Chopin, he’s not so good when it comes to what he calls “pop”.

And that leaves me. I took up the drums about six months ago and have had seven lessons. I practise infrequently and have become to the world of sticksmanship what Germany is to the world of cricket.

In my heart, I fondly imagined that one day, many years from now, when I’d become more proficient, I might team up with the some like-minded souls and perhaps play a small gig to a few close friends in a pub. But here I was, volunteering to make my debut, in a week’s time, in a studio full of 700 people, to a television audience of maybe five million.

There’s no medical term for what I was going through. Doctors call it simply “shitting yourself”.

And it became worse when we turned up, a day before the studio recording, to practise for the very first time.

I’d selected Billy Ocean’s Red Light Spells Danger, partly because it’s a good happy pop song ideal for ending a feelgood Comic Relief show. But mostly because there are only a couple of twiddly bits for the drummer. The rest, though fast, is all fairly straightforward.

Except it isn’t. Not when you put other instruments into the mix. I’d always thought the drums are a sort of noise that go on in the background of a song, but it turns out the drummer is the engine room. The man who keeps time. The single most vital piece of the entire ensemble.

Unaware of this, I did my first twiddly bit and sort of picked up with the beat where I’d left off. Much to my surprise, the rest of the band stopped playing, lowered their shoulders and turned to stare at me.

Actually Hammond sort of glared. There was a very real sense that if I did that again he’d kill me. And since I didn’t know what I’d done wrong this was worrying.

When you’re behind a drum kit, bashing away as though you’re in a cage, trying to get out, you can’t hear any of the other instruments. You kind of assume they’re playing the tune and all is well.

But no, rock music is not the anarchy I’d always assumed. It’s actually pure maths. I had to hit the snare at the precise moment Hammond was hitting some aspect of his guitar, and no, he couldn’t just “miss a bit out to catch up”. When I suggested this, he became even more angry.

To make matters worse I was supposed to be achieving 180 beats per minute. And I was . . . some of the time. Everyone shouted at me a lot for this.

And when I said: “Oh well. It’s for Comic Relief. Perhaps people will find my inability to keep time funny,” they shouted even more.

Eventually our singer, Justin Hawkins, formerly of the Darkness, turned up. He was a bit amazed to find the drummer and the bassist squaring up to one another, but after a couple of run-throughs said: “That’s as good as it’s going to get,” took over my drum kit and spent the rest of the day jamming with Hammond and May while I ate crisps.

And so the next day, after seven lessons and two run-throughs, we took to the stage and did our song. And afterwards everyone was very kind to me, in the same way you’re very kind to a four-year-old who’s painted a picture of some flowers. Even though they look like dogs.

The finished product was transmitted on Friday night at 10 o’clock. I hope you were all in bed and missed it.

Times Recommends

• It’s the beginning of the affair
• Afghanistan: still a price worth paying
• Heroes of the downtrodden