The Fugue of Life
The fugues in Bach's Art of the Fugue-- particularly the first few, such as #4 here-- have a similar style, that recapitulates a person's life.
It starts out slow and simple, like childhood, then slowly more complexity is added by adding voices. The new voices echo the original theme, echoing the original life, but then spin off, in the flight, or fugue. When the third voice comes in, in the same notes as the first voice, there is a beautiful maturity, as when a child completes adolescence. Then the fourth voice can be a relationship, the fifth voice a child. The simple theme that started out so slowly is now very complex and busy, echoing the busy, hectic life of maturity. There are parts that are slightly cacophonic, parts that are sweet and parts that are rhythmic and urgent and progressive, these last sections reaching touching anti-climatic climaxes. The original theme runs through the piece, as a gentle reminiscence of childhood. Other themes weave in and out. Then eventually, the hurried phases of the vocal counterpoint slow down, and there is a form of unity at the end that slowly moves as one main voice, that eventually winds down to the sad, slightly sweet end. The end of the fugal life, the end of a person's life.
The interesting thing is that playing a fugue on the piano really feels like living a small life. The piece starts out very slow, and time goes by slow, but as the fugue gets more complex, time seems to go by so much quicker, much like mid-life when one is so consumed by everything going on-- even though from a more objective perspective, time is still moving at the same pace.