Diminished triads are the horror-movie villains of harmony: three little notes that show up, make everything sound like something bad is about to happen, and then refuse to resolve until you make them. Most guitarists learn one spooky shape, use it once in a Halloween jam, and never speak of it again. That is a tragedy, and this exercise is the intervention.
This is Exercise #27, and it runs diminished triads through the circle of fourths on just the G, D and A strings. No big stretches, no fireworks — just three voices leaning into each other and moving by the smallest possible distance. It is one minute long and it will quietly teach your fretting hand more about voice leading than a whole week of strumming ever will.
How diminished-triad voice leading works
A diminished triad is a minor triad that skipped breakfast: root, minor third, flatted fifth — two minor thirds stacked on top of each other. Because the intervals are identical, the shape is symmetrical, which means every note can act as the root and the same grip repeats every three frets. On the compact G-D-A string set you get three tight voices sitting side by side, perfect for hearing each one move. Moving around the circle of fourths (G to C to F and onward) is the classic path harmony loves to travel, and the trick is to not jump to a new position. Instead, hold the notes that can stay put and slide the rest by a half or whole step to the nearest chord tone. That is voice leading in one sentence: keep common tones, move everybody else the shortest distance.
The concrete takeaway: pick any diminished shape on these three strings, then find the very next diminished chord in the cycle by asking "which finger has to move the least?" instead of "where is the next shape?" Do that ten times and you have mapped the whole neck without memorising a single diagram — the same logic that powers triads and inversions everywhere else on the fretboard.
Warning: once your ears fall in love with smooth voice leading, ordinary chord-jumping starts to feel like teleporting instead of walking, and there is no going back. Want the PDF and the Guitar Pro file so your fingers can suffer in high resolution? It is all on my Patreon.