Prepared Solo
A while back, my teacher told me about the benefits of composing or writing out one's solo (as pertaining to improvising through a set of chord changes). I found it hugely beneficial, in that it required that I spend time carefully studying multiple possibilities of what could be played over a certain harmony, planning out motifs and transitions, and exploring different rhythms. I had started writing out a solo for a recent work, preparing to record the work and the composed solo. When I brought the sketch of the solo to my teacher, and told him about my upcoming recording, he advised me against recording the prepared solo. He explained that preparing a solo as a method of study is excellent practice, and has numerous benefits. However, recording a prepared solo instead of improvising one on the spot removes the element of uncertainty, and in his opinion, renders the solo 'dead.' There is a certain life that only exists when the mastery of improvisation is called upon, and it cannot be replaced with something written beforehand. There is no substitute.