Triads are the building blocks every guitarist learns first and most quickly forgets to think about. The basic major/minor/diminished/augmented triads are usually buried under more advanced voicings — drop-2, drop-3, the various rootless extended structures — and only re-emerge once a player starts working on voice leading or open-position arrangements. That's a missed opportunity, because triads, especially when treated as clusters, are one of the most flexible harmonic resources on the instrument.
Tom Lippincott's MMC series Diatonic Triads Complete (available across his master page) works through all the triadic structures available in major, melodic minor, and harmonic minor — including the cluster triads that produce some of the most distinctively modern sounds in jazz guitar harmony.
What "triad clusters" mean here
A triad cluster, in Lippincott's framing, is any three-note structure built from three consecutive notes of a seven-note scale — C, D, E from C major, or D, E, F, and so on. These structures are dissonant by classical standards (a major second is the tightest non-unison interval) but in a jazz context they produce a rich, modern density that sits well over modal or static-harmony passages.
Diatonic Triads Complete Pt. 5: Clusters works through the full inventory: starting with the close-position cluster, then inverting it across string sets, then opening the voicings up by displacing notes by an octave.
Close vs. open: different jobs
Close-position triad clusters — all three notes within a single octave — have a tight, almost bell-like quality. They're useful for adding bite or color to a melodic line, or for comping inside a single register without crowding the bass.
Open-position clusters spread the same three pitches across more than an octave, usually by dropping one note down or pushing one up. The same harmonic content, but the texture is more transparent — the chord doesn't sit on top of the soloist, it surrounds them. For chord-melody arranging or solo guitar work, open-position cluster voicings are often the more useful form because the melody note can sit on top without fighting the inner voices.
Where the series starts
The cluster class is the fifth in the series, and it's worth working through the earlier classes first if you haven't internalized the basic diatonic triads. Diatonic Triads Complete Pt. 1: Traditional Triads covers the major, minor, diminished, and augmented triads diatonic to the major, melodic minor, and harmonic minor scales — across all inversions and string sets. It's the groundwork that makes the cluster work coherent rather than just exotic.
How to actually use them
The most practical entry point for cluster voicings is sparse comping under a soloist — playing rhythmic figures with cluster voicings instead of standard 7th chords. The clusters don't define the chord harmonically the way a shell voicing does (which can be a feature, not a bug); they color the harmonic space in a way standard voicings can't. They work especially well over modal vamps, pedal points, and tunes with long stretches of static harmony.
From there, the natural step is incorporating cluster voicings into chord-melody arrangements, using the close form for tight melodic lines and opening the voicing up when the melody needs space to breathe. The series gives you the inventory and the fingerings; the application is where your own taste enters.
