One of the most misunderstood things in and about jazz (all creative art) is the "process" that artists embark on when developing their craft. It is easy to be seduced by the very romantic idea that the creation of the art (improvisation as concerns this thread) is almost entirely the result of the expression of the "creative muse"; a force that takes over and simply flows involuntarily from the artist. Words like "process", "develop" and "craft" can seem to be in opposition to the romance. The reality is much more complicated than that and is a combination of both sides of the coin. The great jazz artists have huge intellects and voracious appetites for learning via study and discipline; things that may seem to fly in the face of the free-wheeling attitude that they sometimes portray in their public personas. The greats studied not only the music of other great musicians in other genres, but also meticulously studied and had an encyclopedic knowledge of the classic recorded solos played by other great jazz players. They would learn and often transcribe (write down) these classic solos. All this becomes a part of the musical frame of reference that they draw from on their way to developing their own unique sound or style. This is a great example and may be of interest to some:
One of the classic solos that became famous among players like Red Garland and was carefully studied and analyzed was the trumpet solo that a young Miles played on the tune "Now’s The Time" on a Charlie Parker recording from 1945. Thirteen (!) years later on the Miles Davis recording "Milestones", on the tune "Straight No Chaser" which has similar chord changes as "Now’s The Time" and faster tempo, Garland would actually incorporate Miles’ 1945 solo in his own solo and would play it note for note in his distinctive block chord piano style. Amazing!
https://m.youtube.com/watch?v=b5bQErnsIhgThis is Bird’s 1945 recording in its entirety with Miles playing the famous solo:
https://m.youtube.com/watch?v=c1n4yr4SmA4Miles’ 1958 "Straight No Chaser" in its entirety. Garland plays Miles’ 1945 solo at 7:30:
https://m.youtube.com/watch?v=pthTtLZINHQ