Watch the Diminished Ideas online guitar lesson by Jeff Beasley from Shred Ahead Blues Rock
Being able to take a common idea like the pentatonic scale and embellishing it with an outside idea like the diminished arpeggio, greatly enhances the color of a typical rock lick. The diminished arpeggio is very dissonant which grabs the listener's attention. That being the case, the dissonance or instability of anything diminished requires a resolution to consonance or stability. To achieve this stability we resolve our arpeggio to a common tone in the scale i.e. the root, third or fifth of the underlying chord. Also, an intervallic approach requires a bit of technical ability from the player sharpening skills in both hands.