The story behind
When the Beatles started looking for their first big record hit, they came across a song that John Lennon had written in Liverpool in June 1962. The original idea was a slow song, with a bluesy feel, partly inspired by Roy Orbison's style and a wordplay from a Bing Crosby song that used the word "please" repeatedly. In that first version, the song was quite simple, without vocal harmonies or the harmonica intro we know today.
It was producer George Martin who, upon hearing it, suggested that the tempo was too slow to be a hit. Taking his comment literally, the band returned to the studio on November 26, 1962, and recorded it at a faster speed, adding the harmonica and giving it that boost that would turn it into their first big hit. This version, recorded at EMI studios in London, was released as a single in the UK on January 11, 1963, reaching number 1 on some important charts. The song, which gives its title to their first studio album, was a composition credited to McCartney–Lennon, although the final form had a decisive influence from George Martin.