Bar six of the jazz blues is the one chord in the form that is not a seventh built the usual way. In C it is written F♯°7, and it is the chord most players skip over because the symbol looks like a warning. It is the friendliest chord in the lesson.
This lesson is in C rather than A, for one reason: in A the chord is ♯IV, which is D♯, and the site publishes one spelling for each of the twelve notes. It would show you E♭°7 — the same four sounds written E♭, G♭, B𝄫 and D𝄫. Those double flats are correct and unreadable. In C the chord comes out as F♯, A, C and E♭, which is what you would write by hand.
The four notes, everywhere they fall
This diagram marks every F♯, A, C and E♭ on the first fifteen frets of the guitar.
Every grip above is a handful of the notes on this diagram, and none of them uses a note that is not shown here.
Look along any string. The same four notes come round every three frets, and they do it on every string, because each step of the chord is the same distance as the last — a minor third, four times over, which is exactly one octave. A major chord has a root at the bottom and a fifth at the top. This one is a circle.
One chord, four names
That is why F♯°7, A°7, C°7 and E♭°7 are not four chords. They are one chord and four ways of naming it, depending on which of its notes you decide to call the bottom. Three diminished sevenths between them hold every root there is, so there are only three of these chords to learn in all twelve keys.
The grips, and what each one puts in the bass
Strummed from the lowest string to the highest, this grip sounds F♯, A, E♭, A, C and F♯, which are the degrees 1 ♭3 ♭♭7 ♭3 ♭5 1 rather than the 1 ♭3 ♭5 ♭♭7 of the written chord. The root is the lowest note, so this grip is in root position and sounds the way the written chord suggests. With F♯ in the bass and six strings sounding four notes, the 1 and ♭3 appear more than once.
Strummed from the lowest string to the highest, this grip sounds A, E♭, A, C and F♯, which are the degrees ♭3 ♭♭7 ♭3 ♭5 1 rather than the 1 ♭3 ♭5 ♭♭7 of the written chord. The lowest note is the ♭3 rather than the root, so this grip is in first inversion, written F♯°7/A. It has the same notes as the root-position grip, but with A in the bass it sounds different. With A in the bass and five strings sounding four notes, the ♭3 appears more than once.
Strummed from the lowest string to the highest, this grip sounds C, E♭, A, C and F♯, which are the degrees ♭5 ♭♭7 ♭3 ♭5 1 rather than the 1 ♭3 ♭5 ♭♭7 of the written chord. The lowest note is the ♭5 rather than the root, so this grip is in second inversion, written F♯°7/C. It has the same notes as the root-position grip, but with C in the bass it sounds different. With C in the bass and five strings sounding four notes, the ♭5 appears more than once.
Strummed from the lowest string to the highest, this grip sounds E♭, A, C and F♯, which are the degrees ♭♭7 ♭3 ♭5 1 rather than the 1 ♭3 ♭5 ♭♭7 of the written chord. The lowest note is the ♭♭7 rather than the root, so this grip is in third inversion, written F♯°7/E♭. It has the same notes as the root-position grip, but with E♭ in the bass it sounds different.
Four shapes for F♯°7 on guitar: F♯°7, F♯°7/A, F♯°7/C and F♯°7/E♭.
Every grip here is F♯°7, but no two of them sound alike. A chord with the root as its lowest note is in root position, and a chord with any other note at the bottom is an inversion. On a keyboard you choose the inversion you want, but on a neck the shape your hand can reach usually decides it for you. When a grip sounds a note more than once, the fretting hand decides which note that is, not the harmony.
The grips above are four ways into the same four notes, each with a different one of them at the bottom. Separately from that, because the chord comes round every three frets, any shape you can play is still F♯°7 three frets higher, and three higher again. Exactly one other chord behaves that way — the augmented triad, which repeats every four frets — and you will meet it far less often.
What your box does over it
The blue third, through the form
E♭ bends up over C7 E♭ rests over F7 E♭ bends up over C7 E♭ leans onto D over Gm7 E♭ bends up over C7 E♭ rests over F7 E♭ rests over F♯°7 E♭ bends up over C7 E♭ passes through over A7 E♭ leans onto D over Dm7 E♭ leans onto D over G7 E♭ bends up over C7 E♭ passes through over A7 E♭ leans onto D over Dm7 E♭ leans onto D over G7
Read the row: it bends up over C7, rests over F7, leans onto D over Gm7, rests over F♯°7, passes through over A7, leans onto D over Dm7 and leans onto D over G7. A filled disc is a note you can stop on, a smaller one passes through, a tick under it leans onto the note below and a tick over it bends up into the note above.
Read bar six. The ♭3 — the blue note you have leaned on since Part 2 — rests over the diminished chord, because E♭ is one of its four notes. So is the root. Two of the five notes in your box are chord tones of the chord that looked like the hard one, and you did not have to learn anything to get them.
This lesson was drafted with the help of AI, so it may contain a mistake. Its diagrams are drawn by Everyfret’s own software. How Everyfret is made