The pentatonic guitar scales are the basics for anyone interested in playing lead guitar or just plain jamming with a friend.
These scales are really only shortened major and minor scales. These notes are the most often used in melodies and improvising.
They leave out two notes from the major scale and the natural minor scale which is in the major scale.
Many rock guitar player use these scales exclusively.
They are also the Blues scale minus one note. The Blues Scale can be combined with the Pentatonic scales for improvising.
Just like the major scales have relative minor scales. The pentatonic scales do too.
The C major pentatonic is related to the A minor pentatonic.
The Major and relative minor contain the same notes, they just start on a different note, just like the major scales.
The C chord is in the C, F and G scales.
The major Pentatonic C scale is C D E G A. Below are the major scales that the C chord is in.
See how the C major pentatonic guitar scales can be used to improvise over any C chord no matter what key you are in. It misses the B♭ and the F♯.
The B♭ would give a dominant 7th sound and the F♯ would give a flatted 5th sound neither of which would fit with the C major except in a Jazz-Blues fusion.
The Am chord is in the C, F and G scales.
The Pentatonic A minor scale is A C D E G. Below are the natural minor scales that the C chord is in.
The A minor pentatonic also misses the B♭ and the F♯. Meaning that you can use the A minor pentatonic scale on any A minor chord no matter what key you are in.
I call the pentatonic scales safe scales because of the notes that are left out from the major scale.
These scales can be used to improvise on any major or minor chord despite what key you are in. No wonder they're so popular.
The major C penta scale contains the triad notes C E G and the 6 and 9, A and D which can be added to any major triad.
In the minor penta the scale contains the minor triad A C E and the 4 and 7, D and G. In this case the 4 or D is used as a passing tone, in other words don't use it as a "home" note.
The C major pentatonic and the A minor pentatonic have the same notes. The difference is how you play them. On a C chord your home note is C and with the A minor the A is the home note.
This is similar to the major scale where the A minor natural minor scale is the same as the C major scale. It just starts on a different note.
What you can do with these scales is change scales as the chords in a song change. This will let you play with the changes instead of playing over them by staying with the pattern for the first chord in a song, that gets boring.
Use passing tones as you change your scale. You can use notes that are in between your chords as you change from one to the other.
If you are playing an A minor chord and it's changing to a G play a G♯ right before the G change or use E♭ before the change to lead into the next chord. This will make your playing sound more professional.
Always be aware of the chord changes so you can tailor your playing to them. Start your lick on the up-beat instead of on the one down beat, be unpredictable but tasteful. This is easier said than done and will take some practice but this is just part of the journey, enjoy it.
I hope you found this page useful.