You can associate a major pentatonic scale position with each C-A-G-E-D chord pattern. This means when you are playing a C chord or a C style barre chord you can add notes from the C scale pattern with relative ease, because the scale pattern is built around the chord pattern. On the left you can see the scale pattern with the suggested fingerings and on the right is the C chord pattern highlighted.
Examples
The examples below are in the key of E. To play in the key we can take the scale pattern above and move it up the neck of the guitar so that the root note (marked with an “R”) is on an E note. In the key of E that would be the 7th fret, so the pattern could be played like this:
