Studio Two, EMI Studios
It wasn't going to be Sgt. Pepper's Lonely Hearts Club Band until "Sgt. Pepper's Lonely Hearts Club Band" came along. That is, the album was not "The Sgt. Pepper Project" until the recording of this Paul McCartney song and Paul's realisation soon afterwards that the Beatles could pretend they were actually "Sgt. Pepper's Band", the remaining songs on the LP forming part of a show given by the fictitious combo. Takes one to nine of the title song's rhythm track were recorded during the 7:00 pm-2:30 am session.