Although it's not discussed very often, The Beatles were heavily influenced by Latin music and South American the rhythms in general.
Indeed, latin dance rhythms influenced much of the pop music world going back to the birth of jazz in around the year 1900, and this influence still continues today with songs like "Despacito."
When The Beatles were just starting out in the very early 1960s, Latin rhythms from rhumba to bossa nova were reflected in pop hits such as "Under The Boardwalk" and "Spanish Harlem." Sometimes the beat was somewhat modified and sometimes it was more authentic, but the influence was felt all over the pop charts. So when The Beatles needed to come up with enough songs to play long club sets in their early days, they naturally included some Latin music in addition to their more commonly-known rock and roll covers.
Check out The Beatles playing the iconic Latin song "Besame Mucho" at the Hamburg Star Club. I this performance, they play it faster than we usually hear it, to reflect the energy of the evening and the young, rock and roll audience:
Besame Mucho: Early Beatles version (faster)
A few years later, The Beatles revisited the tune during a studio jam session. Notice how here they play it slower, which is more like we're accustomed to hearing it played. Paul McCartney also has some fun by "crooning" part of the melody in a semi-operatic fashion:
Besame Mucho: Later Beatles version (slower)
It must have felt very natural for them to use the same kinds of rhythms in their original compositions as well. The slow, lyrical melody and rhythms of their song "And I Love Her" owe a big artistic debt to rhumba's like "Besame Mucho" and other Latin songs of the 1940s and 50s.
I've explored this rhythmic connection in my solo piano version of the song. The melody even implies the same kind of jazzy harmonies that we find in "Besame Mucho," so I've developed these as well. Here are some of the possibilities you can use when playing the tune on piano:
And I Love Her: Complete Beatles Piano #4
The Beatles kept on revisiting Latin-influenced rhythms throughout their career, on such later songs as Paul McCartney's "I Will" from The White Album.
I hope you enjoy exploring these musical connections in your own performances of The Beatles music. Good luck with your playing 🙂