Pop in 1964 was part of showbiz: Once the Beatles hit a certain level of box office, there would never have been any question over making a film. Pop music meant teenagers, which meant fads, which meant the clock was running on the band's fame. The jazzman George Melly, who was writing about pop in the UK press at this time, remembered being convinced several times that the Beatles had hit a peak and their fans would soon desert them. I doubt this was an unorthodox opinion.
A film career might extend the fame a little, and smooth the band's inevitable transition to light entertainment. If the film was an enjoyable romp, so much the better-- John Lennon asked for A Hard Day's Night director Richard Lester on the basis of a comedy short he'd made (later referenced in the film's famous "Can't Buy Me Love" sequence), but Lester had also helmed 1962's It's Trad, Dad!, a snapshot of the British pop world just pre-Beatles (Tagline: "The newest, most frantic fad!"). He knew how to mix music and feelgood filmmaking to commercial effect.
A Hard Day's Night, in other words, is a crucial inflection point in the Beatles' career. Coinciding with their leaving Liverpool and moving to London, this could easily have been their first step on a road of crowd-pleasing predictability: Instead, both film and this soundtrack album are a testament to how fabulous pop can be when you take care over doing it.
The album is most famous now for being the first all-original record the band put out-- and their only all Lennon-McCartney LP. Formidably prolific at this point, the pair had been creating songs-- and hits-- for other performers which must have given them useful insight into how to make different styles work. There's been a particular jump forward in ballad writing-- on "And I Love Her" in particular, Paul McCartney hits a note of humble, open-hearted sincerity he'd return to again and again. His "Things We Said Today" is even better, wintry and philosophical before the surprising, stirring middle eight.
But the dominant sound of the album is the Beatles in full cry as a pop band-- with no rock'n'roll covers to remind you of their roots you're free to take the group's new sound purely on its own modernist terms: The chord choices whose audacity surprised a listening Bob Dylan, the steamroller power of the harmonies, the gleaming sound of George Harrison's new Rickenbacker alongside the confident Northern blasts of harmonica, and a band and producer grown more than comfortable with each other. There's detail aplenty here-- and the remasters make it easy to hunt for-- but A Hard Day's Night is perhaps the band's most straightforward album: You notice the catchiness first, and you can wonder how they got it later.