“IT WAS at the 50th birthday party for Dave Gilmour, of Pink Floyd, and he was on the guest list. I thought he’d never show up. He did and I was incredibly nervous, but we talked for a long time and he was incredibly charming.”

No wonder Andre Barreau was edgy: the “he” in question was Beatle George Harrison — the star Barreau had already been playing as a member of the Bootleg Beatles for two decades by then. It was their only meeting and it must have been a weird experience.

As, in a sense, is the whole concept of the Bootleg Beatles, who come to the New Theatre on Sunday evening to perform their cracking tribute to the Fabs. They are uncannily accurate in appearance, movement and, above all, in their recreation of the music. Night after night Barreau, Neil Harrison (Lennon), David Catlin-Birch (McCartney) and Hugo Degenhardt (Starr) — all thoroughly professional musicians — go on stage and portray the most famous pop group there ever was.

I wondered if the real Harrison persona takes over as the curtains open: “Because we’re not actors — we’re imitating as musicians — emotionally I don’t get to that state. But physically, and when I speak, I hope it’s a good impersonation. It’s a concert, not a play.”

He and Neil Harrison have been together now for more than 30 consecutive years playing those concerts (there have been occasional line-up changes with Paul and Ringo) since a show called Beatlemania which they were in had a short-lived run in the West End.

They thought they were good enough stage Beatles to see if they could eke out the franchise a bit longer, but success, at least in this country, didn’t come quickly; Barreau was, as it happens, living in Oxford at the time.

“If you cast your mind back to the late 1970s and early 1980s, there was a feeling around that was post-punk, and the New Romantics came along and generally new-wave music — so who needs the Beatles? That had been ‘then’ and it had been great but . . . The rest of the world, though, had a more reverential approach to the Beatles: Israel was the first big tour, and then there was India and the old Soviet Union.”

Then the break came back in the UK in an unlikely way.

“In 1990, we booked little theatres on our own — no agents would touch us — and got a slightly higher profile. We did Glastonbury in 1994, and Oasis and Blur came to see us. A year later, we were playing in Southampton one night, and Oasis had a day off and came along. We got on very well with them afterwards and then out of the blue a few months later, they asked the Bootlegs to come along and open for them.”

The Bootleg Beatles try to provide the full experience, which naturally means they perform some songs that the originals never did on stage (the Beatles stopped touring in 1966).

So they do the early hits to the closedown Abbey Road/Let It Be era, all in the relevant gear and playing wonderfully close to the true recorded sound — Barreau is no mean guitarist, having played lead guitar, for example, on the Robbie Williams hit Angels.

If you haven’t seen the Bootleg Beatles before, be a day tripper on Sunday: it won’t be long.