Jazz from 1957 to 1967 was the most definitive.

Definition; according to me: "Dixie Land" is "Dixie Land", leave the "Jazz" out. "Rag Time" is "Rag Time", leave the "Jazz" out. "Hard Bop" is not a "genera of jazz", it is a description of the jazz being played, or one LP. Example: Charlie Parker, who is the founder of "Hard Bop",cut "Bird with Strings", which is not "Hard Bop".
"Bird with Strings" contains some of the most beautiful music I have ever heard or ever will hear. According to the experts, "Just Friends", one of the cuts on that LP is perfect, note for note.
Most of my LP collection is no longer available in any format, this is available on CD: "Charlie Parker With Strings: The Master Takes"

Orpheus, there is a well documented and defined lineage of the different "styles" or "generes" (or whatever you want to call them) within the realm of "Jazz." None of these styles or genres exist or came about independently from one another.

Whoa whoa whoa. Bird is the founder of HARD bop ? He with Diz and Coleman Hawkins helped create BOP ( playing with the bridge from Cherokee) but HARD bop ? Foster: I love Miles too. Matter of fact I listen to him A LOT. But I'm with Wynton M. on this one : The three most important figures in jazz (in my OPINION) are Pops, Duke and Bird. Before pops there was no instrumental "solo" as we know it today. He, Buddy Bolden and King Oliver created spontaneous virtuoso solos. Along with this he created the template for modern popular singing. Everyone since owes what they do to him. He called what he did rag time but it isn't what we would call raftime. He was refering to "ragging the tune". Essentially slow blues which was sweaty and dirty and got dirtier as the night went on. Duke added a kind of musical sophistication that might be unmatched by any other individual. He was a terrific song writer and a terribly under rated piano player. Bird helped create the genre of bop. He also was fluent in both the "deep blues" (ala Lester Young) AND the modern harmonics of people like Diz. Very few others were - maybe Dexter Gordon. His improvisation was unmatched. I do love Miles' fostering the cool jazz genre as it brought back some swing to a very undancible bop genre. He then progressed to hard bop,free jazz and fusion. I just don't think on balance it was as important for what came after him as the other three were for what came after them. If I had to pick just one individual it would be Pops. Not because he is my personal favorite but because we would not be having this discussion without him. - Jim

Fun discussion!

Reminds me to give Ken Burn's Jazz Mini-series a play again sometime soon. I recorded the entire series on vhs back when it first ran. That is a must view resource for anyone who would like to learn A LOT about the history of jazz and its makers!

Well said, Aldavis. I think you set the record straight.