Ken Dodd talks ahead of Birmingham show

The Master of Mirth is a comedian of legendary status and will headline Birmingham's New Alexandra Theatre tomorrow.

Ken is an icon and national treasure who has been entertaining audiences for a lifetime. Fans can look forward to enjoying his famous Happiness Show where they'll be absolutely discumknockerated (that's Knotty Ash for 'over the moon') by a truly tattifelarius (fun-filled) evening of laughter and songs from Opera to ballads.

His shows famously last for hours and hours and it's not unusual for fans to still be in the theatre at 1.30am.

"My job isn't to educate people or even do politics. I've got to make people feel good, I want to make them happy."

Though he's now 89, he has no plans to retire.

"Retire? Never! It takes it out of you – believe me you know when you've done a show, it takes a day or two to recover.

"I don't feel 89. But what would I do if I retired? Oh god, no. You couldn't find anything as fascinating as this – maybe, the only thing I could think of that would be as good as this would be gardening; the secret of happiness is to plant a seed and see it grow; the secret of keeping going is to feel that you're necessary; to feel that you've some use in life. To feel completely useless, that's awful I couldn't sit on a beach – oh no, that wouldn't be me. I suppose I could sit on a beach and write but no, I've got to take part . . ."

Besides, Ken couldn't live without the adulation. Bob Monkhouse famously said of him that everything off stage was an interval. "When I played the Palladium in 1965, a huge wave of welcome hit me. I didn't think London would welcome me. But the Palladium is actually a provincial theatre in London. It's really working class."

Ken started his career in 1954 and has seen it all. In the 1960s his fame in the UK rivalled The Beatles and his recording of Tears was the UK's third-best-selling single of the 1960s.

And yet despite his experience, he still gets nervous before a gig. "I still feel apprehensive before a performance, especially if it's an important show. Like my first opening night at the Palladium . . . God, I remember that: I lost a stone before I got to the dressing room. You feel agitated, like a horse in the stalls before a race."

He's never completely satisfied, even after a show. And he records the quality of his own performances on his Giggle Map, which shows the varying responses to different jokes and routines across the country. He enjoys photography and says his favourite photograph is a rear view of him walking through a theatre car park after a performance: "It's the clown leaving at the end of the show, thinking about how things went: thinking that joke didn't go down too well, or I could have told that one better. The trick is to polish the act like a jewel and you get to know what works for an audience."

Though Ken has a lifetime's full of material, he can't resist the temptation to try out new jokes each time he takes the stage.

"I still try six new gags a night. But sometimes lines hit the deck. Sometimes it's you, or the timing, or whether you touch a never. Some love husbands and wives jokes. Sometimes it's the throwaway line that gets the bit laughs. I tried one the other night. 'Time is a great healer, but a terrible beautician'."