>Edit: can't imagine why anyone would downvote that suggestion? Care to say why rather than just downvoting?
And I did just that.
>and acting like a pretentious jerk takes away from any point you were trying to make.
I'll point out that you're the one making unsubstantiated claims and resorting to ad hominem attacks (against me as well as a reviewer who you didn't read very thoroughly). Meanwhile, I'm not pretending anything: my critiques of Levine are substantive. Would I recommend his book to a beginner to jazz? No, for the reasons I outlined above. I think it's fine for someone with a bit of experience (and even then, I'd point them to the Jazz Piano Book), but my opinion as someone who has read extensively on music is that there are better an more comprehensive offerings at this point in time.
Yelling "pretentious" at critiques that are supported with cited evidence doesn't do a whole lot for your credibility, or the word itself for that matter.
This should be one of the first questions to be asked. You can't learn it unless you're listening to it and depending on what kind of jazz you're aiming for, there's different schools of thought.
In any sense, I'd highly suggest Mark Levine's The Jazz Piano Book along with a Real Book (or any lead sheets you can get your hands on)
2 things: jazz piano teacher, and this book .
Also, play a lot with other people & improvise.
It was honestly just lots of doing it. I will admit my situation and the positions I've found myself in are somewhat unique in lending themselves to it.
I didn't get stated playing seriously until I was already pretty old (26) which means there's hope for anyone. However, at that age I already had a music degree and while having a lot of background in the fundamentals of music was useful, much of what I do now is a world apart from anything I was taught formally.
I got a job accompanying (despite my lack of piano background) at a black school. I mean, it wasn't all black or anything, but it's honestly just a rural black school in Texas. I often wasn't given music ahead of time if at all and had to learn to comp from chords. I've heard people argue I just naturally have a feel for it. My wife would beg to differ. I'm a slow learner in all honesty. Whatever I had "naturally" has probably just come from lots of listening. Growing up it was probably a lot of plain ole (white) praise and worship style music that maybe it easy for me to adapt to the comping idea.
But now I was being forced to learn a lot denser harmonic stuff and I did because I had to. I dipped lightly into jazz (somewhat blindly at the time) to understand more theory about what I was trying to play.
I later joined a cover band full of older musicians doing all styles, but with lots of R&B. Basically, doing a lot of that music and gigging with them for 5 years or so has put in me in a position to be playing the same songs a lot and having a place to try creative different ideas constantly. There's also a weird something about the energy of playing live and with real musicians that I swear just makes you try things. I also just had a lot of exposure to that stuff, including lots of music that would honestly be culturally outside of my normal exposure.
So one part of improv is listening and emulating, but if you don't know what to play technically or how to use your ear, it won't just happen magically. In the early days I spent a lot of time just physically doing a lot of chord exercises. I'd basically pick a chord type, play it in root, 1st, 2nd, 3rd, inversion and back down in every key around the CoF, then do the next chord type. I basically made sure very block chord voicing was under my fingers for major, minor, maj7, 7, m7, m7b5 (and I should've done more dim7 because I'm still slightly less good at them).
The band also did a lot of jazz standards for things like dinner music. I got asked to take a small jazz combo gig from an acquaintance (trumpet, bass, keys). Like most of the jobs I've taken, I was not really ready for it, but I jumped in with both feet and really started digging deeper into jazz and jazz theory to compensate.
Learning to understand the importance of 3 and 7 in spelling chords as well as spending lots of time playing ii-V-Is with various voicings just expanded my palette. Meanwhile I'm still gigging everywhere with the band and taking up extra combo stuff on the side and doing some extra duet stuff with my wife so I'm getting lots of real world situations where I have to put these things to actual use.
Now I'm much more more familiar with materials I wished I'd been familiar with back then. This book for getting started with understanding jazz and how to work a leadsheet would've been useful earlier. This book for understanding more of the theory and comping patterns in so much of the pop music I was playing would've been a godsend. The Mark Levine book is one I spent time in before I should've and is why I recommend the Mark Harrison book first for people who aren't super grounded in that style.
But now a lot what allows me to do what I do is understanding what's necessary in a chord, what's not, having lots of patterns under my fingers by practicing in every key, being able to quickly just know what part of a chord something is. If you asked me the 3rd or 7th of any chord I would know it instantly. I'm also pretty quick at most extension too. I also know what I chord I need to play to create a rootless 9th quickly (like Ebmaj7 if I want a Cm9), and other types of upper structure ideas (like wanting a Bm7 on top of C or a D major on top of Cmaj7 to create a Cmajor13#11). Many of those ideas you can practice in your head away from the keyboard. Understanding pentatonic scales also helps you very quickly throw out a lot of color notes and fills that area always safe.
So basically, tons of practice, but I'm not sure I'd be able to do i if I wasn't regularly playing 2-4 hours gigs where I was forced to put this stuff into practice. It definitely puts a little extra fire under your butt when you're getting paid and especially if you aren't as good as you should be. Having to learn more charts than I could ever memorize and occasionally doing jobs where I'm literally sight comping charts I've never seen has pushed me to get really good at chart reading.
A true jazz equivalent will not be on a page.
Closest I can think of is working out of the Mark Levine book . Pick a voicing idea, practice it around the CoF. Now apply it to several standards. Bonus points if you do them in every key as well.