alternatehistory.com

POD 1965
Brian Wilson has his first mental breakdown on tour with the Beach Boys.
In OTL, the result is that he quits touring to concentrate on writing songs & producing their recording sessions.. but what if the illness is much, much worse?

Brian retires from music altogether.. the rest of the band carry-on pretty much as a surf band. The classic album 'Pet Sounds' is never written.

What impact does this have on the Beatles, and pop in general?

Bearing in mind that Pet Sounds is cited as a huge influence on Sgt Pepper.. I'm thinking the Beatles 1967 album will have a harder edge to it than Sgt Pepper did... possibly getting hard rock kick-started a few months earlier than in OTL?
Top