Forget about learning "the whole Real Book;" how about learning every song on your five favorite jazz records?
Jeremy's suggestion is great I often tell students to play along with a record they like and learn to play all of the tunes from memory.
Anecdote: I did a workshop a couple of years ago with a student ensemble who had never played together before. I asked them what they wanted to play and the bass player called 'So What.' (Great that he knew 'So What'). Then all of the other players got out their phones to look up the chart. After we had a little reality check and agreed that we could all remember the two chords in 'So What,' we played it with no charts. The problem did occur that not everyone could remember (or hear) when the Ebmin7 chord was supposed to happen but that points out a problem with concentration and listening.
My suggestion afterwards was that they all go back to Kind of Blue and learn "Freddie the Freeloader," "All Blues," "Blue in Green," and "So What" from memory by playing along with the record ("Flamenco Sketches" is a little trickier due to the fluid harmonic movement).
I've always been a fan of just putting on a record that I like and playing along with it. Sometimes I'll refer to a chart, but I like to get to the point where I just hear the harmony and can play it.
If it's a standard-type tune, I prefer to just play the tune (i.e. if you want to teach me a tune with functional harmony, just play it for me, and then let me play it along with you). If the tune is a complicated, modern tune with non-functional harmony (like advanced modal tunes), then it will help me to see a chartI can see and analyze the chart theoretically and then relate that right-brain info to my left-brain intuition (the "I'll-just-listen-and-make-music-out-of-this" side of my brain). Eventually I will know that tune also, but it helps to know it from both sides theoretical and practical.
It's very important to be able to read, but some players in some scenes don't need to read much at all. Conversely, some players in other scenes don't need to know a lot of tunes, but they need to be able to read welland make the reading sound natural (like it is spontaneous and alive).
Since I work with a big band full time, I read a lot of charts (sometimes, very long charts). But from my days in NYC, I also maintain the "don't use a chart unless you have to" mentality. I think that has changed somewhat with younger players who mostly play original music and very few standards.
It helps to know a lot of tunes, and it helps to read very well. The two skills are not mutually exclusive.
Zojo: Of course you can't really tell on a record who is reading and who is not. If the musicianship is at a high level, then it doesn't matter. That means everyone is listening and reacting in the moment, plus all of the details of harmony, melody, rhythm, and dynamics are accurate and compelling.
Chris has a good point:
We all find our own balance somewhere between the player with "ears like Dumbo" and the player who "can read fly$".
