Mozart a biography

is an excellent book by Piero Melograni (isbn 0-226-51961-9). As usual I'm going to quote from a few pages:
Mozart was great (among other reasons) because he knew how to have fun.
Some people believe that music flowed from him almost spontaneously, thanks to his genius. In reality, from earliest childhood he practiced for thousands of hours every year.
He lived only thirty-five years, but he lived them at a wolf's pace and went far in that short time.
In a letter dated 20 August 1763, Leopold Mozart relates that in many places in Germany the well water was so bad, smelly, and muddy that it was habitually mixed with wine. It was worse in Paris. Parisians drank the repugnant water of the Seine, into which the city's garbage was thrown. The Mozarts, like many others, let it settle in a pitcher for a few hours, where it formed a worrisome solid layer.
In a letter dated 1 April 1764 Leopold reported that when an eclipse of the sun had occurred, Parisians rushed into the churches to protect themselves from being poisoned by the air during the temporary disappearance of the sun's light.
Wolfgang fell seriously ill with smallpox. He was blind for nine days and hovered between life and death, for the second time, after his bout with typhus in 1765.
Mozart performed several times on the harpsichord, astonishing his listeners with the agility of his hands, his left hand in particular. Some Neapolitans, perhaps influenced by a culture that tended to superstition and like mysteries. asserted that the boy played as well as he did thanks to a magic ring that he wore. When they demanded that he take off the ring and play without it, they saw that his playing depended on talent rather than spells, and they applauded all the more.
In those days, a composer would not dream of writing the arias for an opera without consulting the singers who were to interpret them… composers were craftsmen, paid by the piece, and were completely subservient to the true superstars of the age, who were the singers.
In those days no one hesitated about applauding in the middle of a work of music.
His fingers were deformed, either because of continual keyboard exercises from childhood on or from arthritis.
Only artists capable of innovation can give a long life to their works. Innovation prompts tension, curiosity, and awe.

complexity

From The Way of the Leader
Do the essential things well: Be proactive (do through action), Reduce complexity (concentrate effort on the essential things), Seek improvement (get the essential things done better).

From Everyday Heroes of the Quality Movement
Automating complexity is never as effective as removing it.

If you automate without first getting rid of complexity, you cast the complexity in concrete.

From Simplicity
The human brain is a very simple system that is capable of working in a complex way, rather than a complex system.

From Patterns of Software
In the modern era, we have come to favor simplicity over complexity, perfection over imperfection, symmetry over asymmetry, planning over piecemeal growth, and design awards over habitability.

From The Gift of Time
Complexity isn't an attribute; it's a relationship.

From General Principles of System Design
Complexity is a relationship between system and observer.

From The End of Certainty
A nonequilibrium system may evolve spontaneously to a state of increased complexity.

From The Systems Bible
A complex system that works is invariably found to have evolved from a simple system that worked.

From Surfing the Edge of Chaos
Recent study of evolution, both in the natural world and in computer based complex systems, has demonstrated the surprising result that the presence of parasites in a system accelerates evolution dramatically.

From Consilience
Complexity is what interests scientists in the end, not simplicity.

From Adapt - why success always starts with failure
Complexity is a problem only in tightly coupled systems.

From General Principles of Systems Design
There is a tendency for complexity in models to rise as the time between sensing and acting grows.

Photo by Kevin Wong.