Now let's look at a more complex chart:

http://www.jazzguitar.be/images/lessons/ATTYA-Key-Centers.gif

Here the key centers are given above the brackets and this time they change throughout the song. So even though the key of the song is Ab major, some of the key centers have us playing in C maj, G maj and E maj. But wouldn't that clash? No. Try it. It's perfect and beautiful sounding. Again, following the chords and the actual key doesn't matter. The accidentals automatically fall into place. Isn't that beautiful?

Look at the first key center progression—F, Bb, Ab, Eb, Db—right along the circle of 5ths on the "fourths" side (counterclockwise). The second key center is C major and the progression is D G C or ii-V7-I. Again, lined up in row along the circle of 5ths. What could be more beautiful than that? The G major key center uses the same progression—ii-V7-I—check it out.

Now you might ask how a bassist would use this chart. He can't strum the chord so he'll play each note separately in a variety of patterns that he can choose from. It's how jazz bassists walk the bass. You probably never knew how they know what notes to use from one bar to the next. Now you know—they play the notes in the chord indicated for that bar. If there are two chords in a bar then he play both using just root-5th for each or maybe root-3rd—whatever he wants. Wow, how cool is that?!

And look! It doesn't matter what the clef is! Every musician can use the same exact chart for his instrument! Even modern classical composers make use of this system. Folk can use it, rock can use it, country can use it. Write a song and make a chart out of it and watch all the hidden musical secrets spill out of it and then embellish it and see how you have virtually infinite variations you can make of that song nd can mix them together on the fly if you want to.