It's true. The Kinks lost the plot a little bit in the '70s. But who didn't? Ray Davies had long since tired of churning out albums of pop tunes, and had started tying the songs together with an overarching theme. This conceptualism started with Village Green Preservation Society and fully reared its head on Arthur. But it wasn't until 1973's Preservation--which picked up strands from Village Green--that the Kinks tried a full-on piece of musical theater.
And, no, it wasn't very good. Spread out over three discs (1974's Preservation Act II was a double album), the whole project was a bit of a disaster, with characters and stories and social commentary coming together for a murky, pretentious stew. There's a fellow named Flash, who signifies Capitalism, and his opponent Mr. Black, who is Socialism... oh, yawn. Who cares? It didn't work.
And yet there were still nuggets of great music buried in the mire, such as "Sweet Lady Genevieve," which was buried on Side 1 of the first Preservation album. You can entirely ignore the fact that it's sung by a character named the Tramp, and focus on the Ray Davies-patented combo of sweet love song with dark twist. It's as good as anything the Kinks ever did.
The Kinks - "Sweet Lady Genevieve"