Formal structure of  "Here Comes The Sun":
+ keyboard 0:07-0:14
Verse 1 0:27-0:43
Instrumental ext. 0:55-0:59
Verse 2 0:59-1:14
Middle 8 1:31-2:12
Verse 3 2:12-2:27
Coda (M8) 2:59-3:05
Comments: "Here Comes the Sun" is the first in a while to use a 2-part intro, with the solo guitar being heard first, followed by the keyboard. This was a very common tactic in early Beatles recordings, but has become less common in the later recordings. The band used 2-part introductions previously in [6b] "A Taste Of Honey",  "Thank You Girl",  "Little Child", [14b] "Roll Over Beethoven",  "You Can't Do That", [31b] "Matchbox",  "Baby's in Black", [38b] "Mr. Moonlight",  "I Feel Fine", [46e] "Honey Don't",  "Ticket to Ride",  "Run For Your Life",  "Norwegian Wood (This Bird Has Flown)",  "If I Needed Someone",  "Tomorrow Never Knows",  "Love You To",  "Paperback Writer",  "I Want to Tell You",  "She Said She Said",  "Lovely Rita",  "Getting Better",  "Within You Without You",  "Baby, You're a Rich Man",  "All You Need Is Love",  "Revolution 1",  "Don't Pass Me By",  "Good Night",  "Ob-la-di Ob-la-da",  "Helter Skelter",  "Mother Nature's Son", and  "Octopus's Garden".
The middle 8 consists of the same six-measure phrase repeated 5 times (i.e. heard a total of 6 times, the first of which omits the vocals) followed by a transition that both climaxes the song and leads back to the third verse.
One thing I have occasionally noticed about the formal structure of Beatles songs is the way they climax about two thirds of the way through, followed by a return to the verse. I have often wondered about a connection between that and the climax of classical Sonata Form, which similarly climaxes about two thirds of the way through when the development section segues to the recapitulation. There's more to be written on this notion, but that will be an entire blog on its own rather than part of this one.
Lastly, the final chorus features not one, but two extensions that help propel the song to it's conclusion.
Music can very loosely be broken down into two primary constituents: pitch (which is to say how high or low any given sound is), and rhythm (how short or long any given sound is). As I wrote in my 2013.01.26 and 2013.01.31 blogs, "Something" illustrates how George Harrison's compositional maturity encompassed pitch through the music of motivic unity and tonal structure. And where "Something" shows Harrison's developed sense of pitch, "Here Comes the Sun" shows his developed sense of rhythm.
Most music is written in quadruple meter, meaning four beats to every measure. In fact, that meter is so often used that it has earned the nickname "common time". "Here Comes the Sun" is mostly in common time, however at the end of each verse and especially in the middle 8, the meter changes. This is illustrated in the score example below.
A string of 3/8 bars helps conclude each verse, and reappear in the middle 8 along with a 5/8 bar. It is no coincidence that the climax of the song occurs immediately after the middle 8, with its constantly changing meters, as it transitions to the third and final verse. These changing time signatures help create tension, propelling the song to its climax.
This blog is a workshop for developing my analyses of The Beatles' music.