OCTOPUS

Five boxes. Seven modes. Too many shapes.

Stop memorising boxes. Know what you're playing.

Octopus is a guitar neck where every note shows its interval over the root: 1, b3, 5, b7. No CAGED shapes and no positions to learn by heart. You build scales, arpeggios and chords from the intervals, anywhere on the neck, and you always know which note you are on.

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The Octopus neck showing G7 on every fret, each note labelled 1, 3, 5 or b7 The Octopus neck showing G7 on every fret, each note labelled 1, 3, 5 or b7
G7, frets 0–15. No shape to remember: 1, 3, 5 and b7, wherever they fall.

How it reads

Every note tells you what it is.

Colour shows the job a note does in the chord, not its pitch. After a week you read the neck by colour: chord tones solid and loud, tensions outlined and quiet.

1
RootHome. Everything is measured from here.
b33
ThirdMajor or minor. The chord's quality.
b55
FifthStructure. The ring keeps it apart from the third.
b77
SeventhThe note that makes it a seventh chord.
91113
TensionsColour on top. Outlined, never louder than the chord.

Six of my arms are guitar strings. Not one of them memorises boxes.

Only the two highest strings lit, with Cmaj7: the 3rds and 7ths line up end to end
Cmaj7 on e and B. Thirds and sevenths, end to end.

String sets

Study the neck sideways.

Keep only two or three strings and follow a chord along the whole neck. On a pair you see how the 3 and the 7 move from one string to the next; on three strings you start hearing triads. The arrows slide the set one string at a time.

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D Dorian over two neighbouring zones, mid-playback: numbered notes trace a diagonal line up the neck
D Dorian, two zones, playing. Each note lights up as it sounds.

Zones, not boxes

Play across the neck, not inside a box.

Pick a four or five fret area, or several, and play through them on a diagonal. Every run starts and ends on the root. The neck shows the note that is sounding, the ones already played and their order, at any tempo, with real guitar samples, a click and a drone.

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Find it: the roots are shown in orange and the question asks for every 5 of E between frets 6 and 10
Find it. From the roots, find every position of a degree.

Practice

Then put the book away.

Four exercises turn reading into knowing. Each one names the musical fact when you get it wrong, so you learn the interval, not the dot.

  • BuildA chord and a zone, an empty neck. Tap every chord tone.
  • Find itThe roots are lit. Find every 3, every b7, every 9.
  • Ear trainingHear a note, find its degree on the neck. Root or drone when you want it.
  • StudyA clean, full-width neck with a tempo bar, for playing along.

I don't do shapes. I do intervals.

On the phone

Five frets in portrait. The whole neck in landscape.

On a phone held upright Octopus shows a five fret window with big notes to tap, and follows the playback along the neck. Turn it sideways and you get the whole fretboard. Left-handed players get a mirrored neck with one switch.

Share a link and the other person opens exactly your neck: key, scale or chord, zones and strings. Useful for teachers.

Octopus on a phone in portrait: G7 in a five fret window with Play and What & where buttons

Know what you're playing. Always.

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