What is interesting is that it's said that the Beatles could neither write nor read written music. At least not initially.

Therefore, one simply has to assume that none of this was actually planned from a music theory point of view. They were "writing" the songs as they created and heard them in their heads and later, when someone who could write the sheet music and scribed it onto the written page, the creative musical genius was revealed when, to make it fit the actual music, differing time signatures were absolutely required to allow someone playing from that sheet music to recreate the song accurately.

I think they simply started with a musical idea and then as it evolved, were saying, "hey, lets do this!" and if it worked, they kept it.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.