1. It's back in A major. Why is once again uncertain.
2. Harrison's slide guitar has been omitted. It was found in take 1, and used in later takes, but take 4 does not use it.
3. Paul's mellotron playing is now the intro instead of the outro.
4. That same mellotron progression now underscores the verses, too, replacing the guitar accompaniment found in previous takes.
5. This is the first instance of the chorus preceding the first verse. This provides a much more effective beginning because the lines "Let me take you down, 'Cause I'm going to Strawberry Fields" compel a listener to join Lennon on a journey, as opposed to opening with the philosophical lyrics "Living is easy with eyes closed..."
6. The coda has been completely revised. In addition to Paul's mellotron being put at the beginning instead of at the end, this take is clearly meant to fade out, whereas the ending of take 1 did not necessarily need such a fade.