B♭ diminished 7th arpeggio on ukulele

B♭ · D♭ · F♭ · A𝄫

The course explains what this page shows in Lesson 7 · Sevenths.

The notes

  1. B♭1
  2. D♭♭3
  3. F♭♭5
  4. A𝄫♭♭7

The B♭ diminished 7th arpeggio is B♭, D♭, F♭, A𝄫.

You may also see it called 1 ♭3 ♭5 ♭♭7.

On the staff

B♭CD♭E♭F♭FG♭A𝄫AB♭

On a treble staff, the B♭ diminished 7th arpeggio is written B♭ D♭ F♭ A𝄫.

The solid notes are the B♭ diminished 7th arpeggio. The pale notes are the rest of B♭ harmonic minor, the larger scale it is carved out of, so you can see which notes it leaves out.

Why the B♭ diminished 7th arpeggio has these flats

  1. B♭1
  2. T+S
  3. D♭♭3
  4. T+S
  5. F♭♭5
  6. T+S
  7. A𝄫♭♭7
  8. T+S
  9. B♭8

A scale is a pattern of steps, and this one is T+S T+S T+S T+S: a tone and a half, a tone and a half, a tone and a half, and so on. T+S stands for a tone and a half, which is three semitones. The pattern is what gives B♭ diminished 7th its sound, and it stays the same whichever note you start on.

This scale has only four notes, so it does not use every letter. It is built on B♭ harmonic minor, and the notes it shares are spelled the same way as they are there.

The pattern still does not fit the plain letters. If you walk the pattern up from B♭, three letters cannot keep up:

  • D♭ — the flat third. The pattern needs a tone and a half from B♭, but B♭ to D is only 4, so D has to fall to D♭.
  • F♭ — the flat fifth. The pattern needs a tone and a half from D♭, but D♭ to F is only 4, so F has to fall to F♭.
  • A𝄫 — the fourth. The pattern needs a tone and a half from F♭, but F♭ to A is only 5, so A has to fall to A𝄫.

None of those accidentals was a choice. Once you pick the note to start on, the pattern decides the rest, and a key signature is a record of the result.

The B♭ diminished 7th arpeggio is written with B♭, D♭, F♭ and A𝄫. B♭ has its accidental because that is the key, and the other notes need theirs because the T+S T+S T+S T+S pattern of steps cannot be spelled from B♭ with plain letters.

The pattern of steps is the part of a scale that never changes. The letter names take sharps or flats to fit that pattern, and a key signature is a record of those sharps or flats.

On the piano

2CD♭5F♭5F♭♭7A𝄫7AB2CD♭5F♭5F♭♭7A𝄫7AB2CD♭5F♭5F♭♭7A𝄫7AB2C♭3D♭4E♭♭6G♭G♯1B♭♭3D♭4E♭♭6G♭G♯1B♭♭3D♭4E♭♭6G♭G♯1B♭C3C4C5C6

The keyboard shows the same four notes as a shape you can see. The coloured keys are the B♭ diminished 7th arpeggio, the pale keys are the rest of B♭ harmonic minor, and you can click any key to hear it.

B♭ diminished 7th arpeggio on the whole neck

GCEA123456789101112131415A𝄫♭♭7B♭1D♭♭3F♭♭5A𝄫♭♭7B♭1D♭♭3F♭♭5A𝄫♭♭7B♭1D♭♭3F♭♭5A𝄫♭♭7B♭1D♭♭3F♭♭5A𝄫♭♭7B♭1D♭♭3F♭♭5A𝄫♭♭7B♭1

22 notes of the B♭ diminished 7th arpeggio are marked across four strings.

This is every place the notes of the B♭ diminished 7th arpeggio fall on the ukulele, with each note's name and its scale degree. The roots are marked so you can find your bearings.

Position by position

Position 1 — starts on the 1
GCEA3456781♭3♭5♭♭7♭♭71♭3♭5
Position 2 — starts on the ♭3
GCEA67891011♭3♭5♭♭711♭3♭5♭♭7
Position 3 — starts on the ♭5
GCEA91011121314♭5♭♭71♭3♭3♭5♭♭71

The B♭ diminished 7th arpeggio has three playable positions, at frets 3–7, 6–10 and 9–13.

Each shape starts on a different degree of the scale and fits inside five frets, so your hand can play all of it without moving.

One climb up the neck

GCEA345678910111♭3♭5♭♭71♭3♭5♭♭7TAB364769710

The climb runs from fret 3 to fret 10 and plays eight notes.

This is one path from the lowest root to the top of the neck, and it plays each note once, never on two strings. It takes two notes on every string. The widest stretch on any one string is three frets.