Of The four in The Beatles George Harrison was highly under rated. He was the guitar sound of The Beatles never really given credit for his music. Harrison also gave us The Traveling Wilburys. Over rated as a musician IMO John Lennon. Great song writer though and a moderate singer. His Secular Humanist /Socialist song called Imagine is about one of the depressing songs ever written.
I first heard "Imagine" on a German radio station in 1972. I immediately thought it was inspired by Marx's Communist Manifesto. However, I didn't know who sang it because the DJ didn't back announce what he was playing, so I assumed it was some obscure American or British Communist balladeer. They didn't play it on the Armed Forces Network's AM station in Kaiserslautern, where I followed the rock charts, so it was several months before I knew who sang it.