I was surprised to see on page 57 of the Beatles' Anthology, Neil Aspinall (their roadie) is quoted with the following.
While some jazz clubs may not have welcomed The Beatles, this hardly seems to have applied to the Iron Door Club. Perhaps Geoff and Clem could comment on how The Beatles were received at the Iron Door Club."There were a lot of gigs in and around Liverpool at the time. There were a lot of ballrooms and townhalls and clubs like the Cavern and the Iron Door and the Blue Angel that bands could play in, but they were mainly jazz clubs. They'd never let the Beatles play. You had to try and force your way in. It was Kenny Ball/Acker Bilk stuff at the Cavern. Thye might let a rock 'n' Roll group play in the break, before the main band came on, a jazz band."