Approaching the diminished arpeggio requires a slightly different tack than with major and minor. The diminished triad is not used much, therefore, the examples here are based on the diminished seventh chord. A G-diminished seventh triad is spelled G, B, D, E. All diminished seventh chords share one very special trait: They are symmetrical. The distance between each of the notes is a minor third; no arpeggios we've studied thus far have had this symmetrical relationship. Symmetrical shapes are a lot of fun on guitar, because their fingerings repeat. Let's look at what symmetrical looks like on guitar. The basic fingering for a G-diminished seventh arpeggio is shown in FIGURE 9-13.

Now you can take this exact finger shape, and move it up the same string three frets higher, and you will still be playing G-diminished seventh. Try playing FIGURE 9-14.

You can keep moving this pattern up three frets, and you will always be playing G-diminished seventh. It's extremely easy to play diminished, because the fingerings across the neck are all the same. If you need to move this into other keys, just look where the circled finger is to find the root. You can move that finger to any root you need and repeat the process up every three frets.

There's another shape that utilizes some lower strings that you can move the same way. FIGURE 9-15 utilizes a G-diminished shape on the second, third, and fourth strings.

You can shift this shape up the neck as well; just move up three frets and the pattern repeats.

There are some shapes that utilize simpler fingerings. Look at FIGURE 9-16 that starts on the sixth string and moves across the neck all the way up to the high string.

To hear diminished arpeggios in rock music, listen to Ritchie Blackmore of Deep Purple and Yngwie Malmsteen. If you'd like to go to the source, J.S. Bach is a great place to start. Check out his sonatas and partitas for solo violin.