But next month on April 13 they play one of their curiously rare dates on Merseyside at the Southport Theatre, their first visit to the venue.
Well not quite their first. Early in the group's career they auditioned at the Floral Hall for the then popular daytime television show Pebble Mill.
"We went on that show three times and even appeared on Points of View with Anne Robinson," he says.. Robinson was not quite so acidic then and praised the band before allowing them to play out the viewers' comment show.
Soon the band had picked up a good living at cabaret dates and particularly corporate events. One corporate booking Alan particularly remembers as the band were flown all the way to Australia first class to play for just 40 minutes.
"We flew back first class for some of the way but were moved to cattle class for the last bit. The deal was we could travel first class as long as there were seats and for some of the trip the first class section was fully booked."
The 9/11 tragedy in New York changed things a bit. "The corporate events suddenly dropped. So we had to re-think."
It was then that the band began concentrating more on theatre shows and are now considered among the best.
Once the show concentrated in part on particular albums, moving from With the Beatles to Help and so on. If they had followed the chronology, they would have been playing numbers from Rubber Soul.
"We tried a few out but it is not what the public wants," Adam says. "They prefer the earlier, easier songs." So the band now delivers a complete package of Beatle numbers and brilliantly enough to win the admiration of former Beatles press officer Tony Barrow.
Like the Beatles, they do a lot of ad-libbing in the show, partly forced on them as the Beatles people do not allow dramatised performances of their story.
"They still get paid for the songs," Alan asserts.
How long Adam can go on with the band is open to speculation. "As far as I am concerned, as long as people want to hear the music, we will keep playing it."
* THE Cavern Beatles, at the Southport Theatre, on April 13, 7.30pm.