Found this on the old blog, thought it would be worth sharing again.
As per Cornelius Cardew, here are essential qualities for a musician to develop – especially an improvising musician, especially a musician who improves “freely:”
- Simplicity – Where everything becomes simple is the most desirable place to be.
- Integrity – What we do in the actual event is important -not only what we have in mind.
- Selflessnesss – To do something constructive you have to look beyond yourself.
- Forbearance – Improvising in a group you have to accept not only the frailties of your fellow musicians, but also your own.
- Preparedness – for no matter what eventuality (Cage’s phrase) or simply Awakeness.
- Identification with Nature – … like a yachtsman to utilize the interplay of natural forces and currents to steer a course.
- Acceptance of Death – From a certain point of view improvisation is the highest mode of musical activity, for it is based on the acceptance of music’s fatal weakness and essential and most beautiful characteristic -its transience.
nate trier 
beautiful and wise words- something all improvisers should practice into their awareness.