The beginning of the song was written by John Lennon and it references a story which he had read in his newspapers on the day of starting the song.
In the Daily Mail, Lennon had read the sad news of the death of Tara Brown, the heir to the Guinness Empire. Brown was killed when he drove his Lotus into a parked van.
The middle section of the song changes as Paul McCartney inserts a piano piece which he wrote for another song. The tempo is upped for this part of the song and the sections are linked by big glissandos played by a 41 piece orchestra.
He added lyrics about a commuter who’s dull journey to work allows him to daydream. This was inspired by McCartney’s memories of travelling on the bus to school, going to class and smoking when he shouldn’t have been.
Lennon wrote the song's final verse which was inspired by another newspaper article which he read in The Daily Express on January 17 1967. It was an article telling how the Roads Surveyor of Blackburn had counted 4,000 holes in Blackburn’s roads and stated that the amount of material required to fill those holes was enough to fill the Albert Hall.
At the end of the song, a final note, lasting 42 seconds was played by all four Beatles and their arranger/producer, George Martin on three pianos. At the end of the recording, the studio air conditioners can be heard as the faders were pushed to the limit.
As the song was the last track on the album, The Beatles wanted to have an unusual way to finish it. So after that long final note, John Lennon suggested that George Martin was dubbed in a high pitched tone which cannot be heard by the human ear, but which drives dogs crazy.
On the day of recording, the orchestra was instructed to wear formal dress. This signified to them that there would be something unusual about the session. When they arrived they were given novelties to wear such as party hats, funny noses, gorilla’s paws, etc. Paul McCartney conducted the orchestra that day.
It’s understood that Keith Richards and Anita Pallenberg named their second son Tara after Tara Brown, the Guinness heir who smashes his car in Lennon's first verse. The baby boy was premature and died soon after birth.
The BBC banned this song in the beginning. It was the line “I’d love to turn you on” that led to the ban. However they changed their minds after a guest on Desert Island Discs, requested it for his playlist.
Rolling Stone magazine listed 'A Day in the Life' as the Greatest Beatles song and it also came in at No. 28 on their list of Greatest Songs of All Time.