I don’t remember calling it rock, but calling it folk because it lacked a few of the pieces of actual music other than telling a story and having a steady rhythm beat. You mentioned Chicago. Blood Sweat and Tears, and Lighthouse were along with Chicago into the jazz/rock medium starting in the 60’s that transitioned from one to the other. But the original changes were coming from the gospel direction with people including Elvis. Bill Haley and the Comets were part of the transition in the late 50’s calling it rock and roll. And that term has been bent and reshaped many times since.
Most of the true big name jazz groups are gone now. The earlys starting with Glenn Miller, The Dorseys, Stan Kenton, Buddy Rich, Basie, Ellington, Cab, up to the last of them with Don Ellis, and Maynard Ferguson. A few of their groups remain in action, but limited. And many of the active ones have taken canned jobs to back TV shows and don’t tour anywhere near when they seemed like they were going nightly somewhere. Sad the changing times.
rwood
"Most of the true big name jazz groups are gone now. The earlys starting with Glenn Miller, The Dorseys, Stan Kenton, Buddy Rich, Basie, Ellington, Cab, up to the last of them with Don Ellis, and Maynard Ferguson."
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Jazz and Big Band isn't the crossover mainstream music draw that it used to be even into the 60s, for sure.
Music in general has become very balkanized since the 60s. For example, there was a pretty good variety of music in on the pop charts back then -
From the psychedelic Blues Magoos to Tom Jones were in rotation on the same radio station.
But there's still a lot of variety of good jazz music around, Youtube is one good resource to find newer artists.
So a person can catch up on some good contemporary jazz while still enjoying classics such as:
Dave Brubeck Quartet - "Blue Rondo à la Turk" live