Reddit mentions of The Blues Fake Book

Here's a more comprehensive answer now that I'm thinking about it:

What gets really messy is when there are multiple key changes. Take a look at some fake books. They'll have the melody, then a bunch of bars that just have the key changes over them. What you're describing is where the G blues scale fits all of the keys.

Take a look at some of the sample pages here:

http://www.amazon.com/Blues-Fake-Book-Leonard-Corp/dp/0793558557

What we used to do was have everyone play the melodies, then go into a solo section. The song (or section of song, depending) would repeat, but the rhythm section would play the chord changes, and one person would improv over those chords.

Now what gets messy is when one scale won't fit all of the chords. You;ll have 4 bars of D7, then 4 bars of G, then maybe one bar of A7 and one bar of something else, then repeat. You run into times where if you play one scale the whole time and miss the changes, it just doesn't work.

When starting out, the best way to be absolutely certain (and this is where I learned all the chord theory that I know for guitar playing), was to learn chord notations, and write down every note in a scale that fits that chord. Do that for every chord on the sheet so you have the scales for each one. Often times, you find that a particular run of chords that happens to have the same scale, like a G blues scale. Sometimes you have to just jump to a different scale for a few bars, other times, you learn to simply avoid certain notes for 4 bars, then go right back to the old scale.

I did improv for a few years and I'm not sure I ever progressed. The difficult thing is understanding what it sounds like to other people. To me, it sounded simple and dumb. Other people seemed to like it. One time I decided to play two notes in a row that were the same - I rode that for quite a while. You start to learn other people's quirks. Our tenor player would always start by playing the scale straight up and a bit stylized at the beginning, then launch into something different. Some people had to play eight notes non stop, which got boring, and didnt really skip around too much, and other people would put large rest periods in (intentionally), and just bop along playing 2-4 notes at the beginning of each change. Simple but effective.

We played so many different songs that making something up and memorizing it never worked.

In the end, the most effective method to get better was to grab some sheet music, the CD that had the rhythm section playing, and just play. Develop your own style. Listen to some of the jazz greats, especially for your instrument. As a sax player, I listened to way too much Paul Desmond and Dennis Diblasio.

If anyone else wants to chime in, go for it.