Open a Real Book chart for the first time and it looks like someone sneezed symbols onto the page: Cmaj7, Am7b5, D7, Gm7 — line after line of them, none of which look like the open or barre shapes you already know. Good news: almost the entire fake-book universe is built from just four seventh-chord types. Learn one shape for each, twice (root on the low E string, root on the A string), and you can already comp your way through a huge chunk of the standard repertoire.
This is the cheat-sheet version of my full walkthrough on simple jazz chords for guitar →, which shows you a real lead sheet ("Autumn Leaves") and how these chords sit on the page. Here we skip the tune and go straight for the four shapes themselves — what they're called, what notes they contain, and the one trick that makes them playable without a physiotherapist on speed-dial.
The four chord types (and their formulas)
Every one of these is built by stacking thirds on a root, the same way a plain triad is — you're just adding one more third on top. According to the standard jazz-harmony formulas used by jazz-guitar teaching sites, the four core seventh-chord qualities and their interval recipes (counted from the root, 1) are:
| Chord type | Formula | Example (root C) |
|---|---|---|
| Major 7 (Cmaj7) | 1–3–5–7 | C–E–G–B |
| Dominant 7 (C7) | 1–3–5–♭7 | C–E–G–B♭ |
| Minor 7 (Cm7) | 1–♭3–5–♭7 | C–E♭–G–B♭ |
| Minor 7♭5 / half-diminished (Cm7♭5) | 1–♭3–♭5–♭7 | C–E♭–G♭–B♭ |
That last one — minor 7♭5 — is also called half-diminished, and it's the chord you'll meet as the ii in a minor ii–V–i (think the second bar of a minor-key turnaround). It shares three notes with a plain diminished 7th chord but keeps the diatonic seventh, so don't mix the two up on a chart.
Why you can drop the 5th and nobody notices
Full four-note jazz chords are lovely, but four fresh fingers on unfamiliar frets is how beginners give up on jazz voicings entirely. This is where the shell voicing earns its keep: it keeps only the root, the third and the seventh, and leaves the fifth out entirely. Teaching sites that specialise in jazz guitar voicings describe the fifth as the one chord tone that doesn't define the chord's quality — the third tells you major or minor, the seventh tells you the chord's "flavour" (maj7, dom7, m7 or m7♭5), and the fifth mostly just sits there. Drop it, and you free up a finger, a string, and a chunk of your patience — with room left to add tensions like a 9 or 13 later, once the three-note shape is second nature. (I cover the follow-up moves — voice leading between shells, and the fuller Freddy Green-style comping shapes — in their own posts.)
Where these charts even come from
That cramped, symbols-only style isn't Real Book laziness — it's the whole point. Jazz was, and still largely is, an aural tradition: musicians learn tunes by ear and improvise around a skeleton, not a fully written-out arrangement. The shorthand of "melody on top, chord symbols above" is called a lead sheet, and compilations of them were nicknamed "fake books" because a lead sheet lets you convincingly fake your way through a song you don't fully know. The most famous one, The Real Book, was put together in the mid-1970s by two Berklee College of Music students who wanted a cleaner, more accurate alternative to the bootlegged fake books already circulating — and it became the standard jazz-jam reference almost overnight.
60-second practice plan
- Pick one chord type from the table (start with minor 7 — it shows up constantly).
- Learn its shell voicing with the root on the low E string, then the same shape with the root on the A string.
- Loop a ii–V–I in one key (in C: Dm7 – G7 – Cmaj7) using only shell voicings, then transpose it up a fret at a time.
- Once all four types feel automatic in both root positions, go back to the full jazz chords guide → and try comping an actual lead sheet.
Once the four shells sit under your fingers without thinking, the next stop is II–V–I voicings on guitar for how these chords actually move against each other, and voice leading for keeping the top note smooth from chord to chord.
If four chord shapes just saved you from buying a Real Book you were scared to open, you can throw a coffee my way on Patreon — no pressure, purely for the riffs.