Trending on Billboard Geoff Emerick was just a teenager in June 1962, employed as an apprentice sound engineer at EMI Studios (later renamed Abbey Road), when a then-little-known English rock band recorded a demo in the studio. John Lennon , Paul McCartney , George Harrison and drummer Pete Best laid down four tracks that day — “Bésame Mucho,” “Love Me Do,” “PS, I Love You,” and “Ask Me Why” — on a magnetic recording tape, which was then shuttled over to record producer George Martin at EMI’s headquarters on Manchester Square. Related You know the rest: After ditching Best for Ringo Starr , The Beatles broke out with “Love Me Do,” launched Beatlemania, and became the most famous band of all time.…