Sir Brucie rocks on his festival debut

A Slice of Britain: After 70 years in the business, the stage and television veteran shows he can still hold a crowd in the palm of his hand

Sir Bruce Forsyth does not scare easily. The 84-year-old national treasure has hosted some of the biggest shows on British TV, coined more catchphrases than he knows what to do with, married a former Miss World, and was finally honoured after seven decades in show business last year with a knighthood, demanded by newspapers, parliamentarians and fans countrywide. It seems there's nothing the King of Variety has not done. But not so.

The sharply attired Brucie tells me he is "not just a little bit, but tremendously nervous". And understandably so. Not only is this the grandfather-of-nine's debut at a British music festival, it is the first time he has ever set foot in one.

As he taps across Hop Farm's main stage, a full 70 years after he first broke into the limelight with his song, dance and accordion act called Boy Bruce, the Mighty Atom, he knows this is one act he is unable to predict. With his tapered moustache framing his wide, toothy smile, he scampers to chants of "Brucie, Brucie". No one is surprised when some of the first words he utters are: "Nice to see you, to see you... NICE." As everyone in the audience puts up their arms and cheers, he smiles, looking faintly relieved.

He is in good company. The Godmother of Punk, Patti Smith, and rock veteran Bob Dylan will follow the British star later this evening. But it seems, momentarily, that he is king of them all. He opens with a simple question, "Where am I?", and the cheers get louder as his jokes keep coming. "I promise you I have never used Jimmy Carr's accountants" is the first, followed by: "I promise you, I am not having an affair with Cheryl Cole." Cue belly laughs, from Brucie, and the crowd.

Next are the songs – think Jersey Boys and Sammy Davis Jnr. He sings standards from his new album, his favourite covers and takes revellers' requests. But the biggest cheer comes when he sings a duet of "Smile" with his 20-year-old granddaughter, Sophie Purdie. There's even a bit of time for a variety classic, inviting three burly men and a penguin from the audience to tap dance with him.

The crowd don't let Brucie down. "The atmosphere was electric, wonderful," he tells me when he is safely back in his trailer. "When you get to the end of your career there are things you don't expect to do. Here I am, performing in daylight – I haven't done a matinee since I did summer season. I am going to put it down as a big tick. I would love to do more."

The festival organiser, Vince Power, noted Brucie might initially seem out of place, a "Rolf Harris" of the festival scene, but added: "He's a curiosity and a huge name. It's great having him here."

And the audience is, well, curious. John Williams, a retired Dylan fan from Yorkshire, said: "The idea that Bruce is on the same bill as Bob is surreal, but I think Dylan would appreciate it." While Amanda Kemp, 52, from Sussex, said: "I've grown up with Bruce. It's nice to see someone I feel like I've known all my life."

As for the man himself, he has had a long day. "It's been nice, but I've been up since 6am," he tells me, before admitting that he won't be staying to watch the rest of the bill. "That's one of the secrets of my longevity," he adds. "I like to pace myself." After this show, I don't quite believe him.