California Sun is basically just a twelve bar blues in Emajor.
For those those who are unfamiliar with the 12-bar-blues, here's an outline
| Take the root note/chord, and play 4 bars of that note, or 4 bars of a
|melody/riff in that key. Then go five frets up the fret board, or play the
|same fret one string up, and play 2 bars of that note/chord, or |melody/riff
in that key. Then return to the root note/chord for 2 more |bars. Then take the
fret 6 up, or 2 frets up on the next string, (or the |same fret one string below),
and do 1 bar of that, and then go 2 frets |down, and do 1 bar of that, then return
to the root, do one bar of that, |then go to the fifth again and do 1 bar of that.
Hey presto! a 12-bar-|blues. I have done some examples.