You can still discover new sounds from the pentatonic scale by using this simple substitution approach. Let's take a scenario guitarists often find themselves in - playing over an A minor groove. We all know that A minor pentatonic works beautifully over this (measure 1).
In a typical rock context, the A minor chord is treated as the vi chord, or relative minor, of C major. Now in the key of C major, the ii chord is D minor, which contains the notes D, F, A, and if you add the seventh, C, and fourth, G, you'll get a D minor pentatonic scale (measure 2). So now over an A minor chord, you have two pentatonic scales you can improvise from. Notice that one of the benefits of this is that just from a visual standpoint, any licks you play in A minor pentatonic can be repeated exactly 2 and a ½ steps up and still sound in key! Measures 3 and 4 demonstrate how I transpose a lick to create a different effect over the A minor chord. Experiment doing this with all your pentatonic licks. The reason the D minor pentatonic scale also works over the A minor chord is that it only adds a new note to A minor pentatonic, F, which is simply the chord's minor 6th. Tune in to future blogs where I discuss other minor pentatonic substitutions that will bring in more interesting note choices to your playing. Follow me on Twitter @halwit and on youtube.com/halromusic for more lessons and transcriptions!
