On February 11, 1963, a record producer by the name of George Martin met four musicians at EMI Studios in London in the hopes of recording an album. The group had already released two singles, one of which had hit number 1 on the New Musical Express and Melody Maker charts. The UK was positively abuzz about the band’s fresh, new sound and Parlophone, a division of EMI, was eager to cash in on this by very quickly releasing an album featuring both singles.

So at 10:00 A.M. on Monday morning, John Lennon, Paul McCartney, George Harrison, and Ringo Starr gathered together to begin recording. The only problem was the band currently only had four tracks ((“Love Me Do”/”P.S. I Love You” and “Please Please Me”/”Ask Me Why”)from the A/B sides of their singles. Martin knew they would need at least 10 more songs to have a complete album–ten more albums in an extremely limited amount of time.

Like, a day.

In a 2008 interview with Billboard magazine, Martin recalled, “”I asked them what they had which we could record quickly, and the answer was their stage act.”

And so that’s exactly what they did.

The marathon recording session “was a straightforward performance of their stage repertoire – a broadcast, more or less,” full of songs from their time at the Cavern Club in Liverpool. On this day, the Beatles worked their way through their live set song by song, the number of takes varying on each, and finished at 10:45 p.m. – less than 13 hours later. It was a day, Martin joked, that “lasted three weeks.” Tracks included the title track and number one single “Please Please Me” as well as other soon-to-be classics such as “I Saw Her Standing There” and “Twist and Shout,” the latter being the last song recorded because Lennon had a cold and Martin knew, due to the intensity of the vocals on the track, “John wouldn’t have any voice left” afterwards.

Although slight tweaking came in the weeks afterward (for example, on February 20, Martin Martin overdubbed piano on “Misery” and celesta on “Baby It’s You”), most of the original recordings remained intact, and Please Please Me, the first Beatles album, was released in the UK on March 22, 1963. It hit the top of the UK album charts in May 1963 and remained there for 30 weeks–before it was replaced by the NEXT Beatles album, With the Beatles, which was released in November of 1963.

Of the 14 songs included on this debut album, 8 were written by Lennon-McCartney, an impressive and revealing foreshadow of the band’s achievements to come. The 585 minutes spent in studio on February 11, 1963 marked the beginning of Beatlemania and changed the landscape of pop music forever.