Assignment #52 asks you 13 questions about parts I and II. Link opens in a new tab.
Cool Jazz (1950s and 60s)
Cool Jazz is simply jazz that is more relaxed and laid-back than bebop.
In our earlier periods, jazz was usually marketed as "hot" and exciting. We've seen that many of the tracks I've selected up to this point are actually fairly high energy. The idea that jazz was something you would listen to in order to relax (while also smoking a cigarette and/or drinking a martini) was an invention of the 1950s.
The first people to play this simpler and less intense form of bebop were white musicians who were based in California, like Chet Baker, Gil Evans, and Gerry Mulligan. Thus, the movement was also known as West Coast Jazz.
Chet Baker (1929-1979)
Birth of the Cool
Cool jazz really hit the big time around 1950 when Miles Davis teamed up with these guys and made a series of lush and laid-back recordings that would eventually become an album called Birth of the Cool.
Miles Davis working with West Coast musicians
Here is a televised performance of music that is in the same vein as Birth of the Cool.
What I think is interesting about this performance is that Miles doesn't play a lot of notes - he just interjects short little ideas here and there. This is part of the "cool" idea - that Miles himself is cool, and he doesn't need to impress you with long, complex lines. Instead, he can play something simple, and it'll be great.
Kind of Blue 
In 1959 Miles Davis gathered together a smaller group to play this new cool style of music. Here, he introduced one new concept, which is known as modal jazz composition. Basically, this took the cool idea one step further by radically simplifying the musical language.
As I've been telling you, bebop was really complex. A typical bebop composition involves lots of different chords, and the challenge is to weave your solo through this complicated structure. It's like a musical labyrinth.
Here's the sheet music to Ornithology, the Charlie Parker composition we listened to on the previous page:
Miles decided to get rid of all this complexity. Instead, he created tunes that only had a few different chords in them.
Here is the sheet music for the tune we are going to listen to, called "All Blues." It only has four chords.
With this simpler structure, the musicians could relax and jam out on a particular scale for long periods of time. These tunes tended to use somewhat exotic scales called modes, so that's why this style of composition is called modal jazz.
Let's listen to "All Blues" from Kind of Blue. We'll hear how incredibly chill the tune is, and then when Miles Davis takes the first solo he starts out very simply, playing short ideas, and he slowly builds from there.
By the 1950s jazz was no longer the dominant style of American popular music. Kind of Blue, however, is the best-selling jazz album of all time. Pretty much every jazz fan has a copy of it.
As the name implies, Hard Bop was another stylistic transformation of Bebop. Here the idea was to infuse jazz with elements from other kinds of African-American music - to put more blues and gospel and early R & B into it.
Here's a classic track by Art Blakey and the Jazz Messengers that you've maybe heard before.
The tune itself is a great example of traditional African-American musical elements. It's got a call and response built into it, in which bluesy riffs are answered by "churchy" gospel chords.
Once the track takes off, the drummer Art Blakey plays a shuffle groove that is also common in blues and R&B recordings.
Some jazz critics have suggested that this was a sort of mirror image of Cool Jazz, taken in another direction. It's also a simplification of the aggressive rules of bebop, but instead of chilling out, this music is infused with soul and intensity.
Charles Mingus (1922-1979)
Charles Mingus was a bass player and composer who grew up in the Watts neighborhood of Los Angeles, California. We can put Mingus in the hard bop category, but in a way he is much more than that. He is similar to Duke Ellington and Thelonious Monk as a creative visionary who produced a very distinct body of work.
Let's jump into the world of Mingus with "Better Get It in Your Soul"
Like with Moanin', this track is packed with energy and intensity. Blues riffs are everywhere, and the instrumentalists often play with a growl-y tone that seems to transcend more "proper" instrumental technique.
If you listen carefully, you can hear that there is a voice doing various blues "shouts" along with the music, calling out "oh yeah!" at key phrases. And around 3:36 the drums and bass drop out and the band claps along in the background, suggesting a sort of church gathering.
Mingus also had a notable soft side, writing tracks that were meant to be contemplative and pretty. Let's listen to "Goodbye Pork Pie Hat."
This was Mingus's tribute to Lester Young, a tenor saxophonist from the Swing era who wore the kind of hat mentioned in the title:
We can hear that this composition is still very bluesy, but more gentle and sad.
Assignment #52 asks you questions about Bebop, Cool Jazz, and Hard Bop.