The Prog Side of The Beatles

There's nothing wrong with including a great non-prog song.  Most prog bands have the odd non-prog song.

They are not Prog Rock or what we define regularly as Prog. Their usage of the mellotron was superb , inventive/creative, and influenced part of the birth of Prog. King Crimson in 69' used to rehearse "Lucy In the Sky With Diamonds" so I attribute their overall influence in the elements/ideas they came up with, (along with George Martin) to produce something unique within a song by using effects and unlike many others who attempted to catch up with The Beatles during the rat race when many bands were trying to sound like Sgt. Pepper. For a while it was almost insulting. It was an influential album, but too many artists were simply out-right copying the style. The Beatles late 60's material presented an idea to combine influences from other styles that were not Rock. The way in which The Beatles produced that as an end product, it became evident to most internationally known artists that they were surrounding the melody unlike anyone before them. The choice to use a sitar, a French Horn, or string quartet to enhance the vocal, creating a style that couldn't always be catagorized as Pop. Maybe years later..it was, but not in 67' when people first heard Sgt. Pepper. What happened later is not any motive on behalf of The Beatles. When it was first released, it felt very strange to people and they were drawn in by it's intensity of sound. That's why it influenced Progressive Rock. It was mainly  an aspect to the actual style that produced new ideas in Prog. It was a premature stage .