B♭ dominant 9th arpeggio on bass

B♭ · D · F · A♭ · C

The course explains what this page shows in Lesson 13 · Sevenths.

The notes

  1. B♭1
  2. D3
  3. F5
  4. A♭♭7
  5. C2

The B♭ dominant 9th arpeggio is B♭, D, F, A♭, C.

You may also see it called 1 3 5 ♭7 2.

On the staff

B♭CDE♭FGA♭B♭

On a bass staff, the B♭ dominant 9th arpeggio is written B♭ D F A♭ C.

The solid notes are the B♭ dominant 9th arpeggio. The pale notes are the rest of B♭ mixolydian, the larger scale it is carved out of, so you can see which notes it leaves out.

Why the B♭ dominant 9th arpeggio has these flats

  1. B♭1
  2. 4
  3. D3
  4. T+S
  5. F5
  6. T+S
  7. A♭♭7
  8. 4
  9. C♯♯♯♯♯♯♯♯♯♯♯♯2
  10. -2
  11. B♭8

A scale is a pattern of steps, and this one is 4 T+S T+S 4 -2: 4, 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. 4 stands for a step of four semitones. -2 stands for a step of -2 semitones. The pattern is what gives B♭ dominant 9th its sound, and it stays the same whichever note you start on.

This scale has only five notes, so it does not use every letter. It is built on B♭ mixolydian, 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♭, one letter cannot keep up:

  • A♭ — the flat seventh. The pattern needs a tone and a half from F, but F to A is only 4, so A has to fall to A♭.

That accidental was not 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♭ dominant 9th arpeggio is written with B♭ and A♭. B♭ has its accidental because that is the key, and the other note needs one because the 4 T+S T+S 4 -2 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

2C3DE5F6GAB2C3DE5F6GAB2C3DE5F6GAB2CC♯4E♭F♯♭7A♭1B♭C♯4E♭F♯♭7A♭1B♭C♯4E♭F♯♭7A♭1B♭C1C2C3C4

The keyboard shows the same five notes as a shape you can see. The coloured keys are the B♭ dominant 9th arpeggio, and the pale keys are the rest of B♭ mixolydian.

B♭ dominant 9th arpeggio on the whole neck

EADG123456789101112131415F5A♭♭7B♭1C2D3F5B♭1C2D3F5A♭♭7B♭1C2D3F5A♭♭7B♭1C2D3F5A♭♭7B♭1C2D3F5A♭♭7B♭1

36 notes of the B♭ dominant 9th arpeggio are marked across four strings.

This is every place the notes of the B♭ dominant 9th arpeggio fall on the bass, with each note's name and its scale degree. The roots are marked so you can find your bearings.

The five boxes

Box 5 — starts on the 2
EADG345678910112135♭7213
Box 1 — starts on the 1
EADG6789101112135♭72135
Box 2 — starts on the 3
EADG891011121314151635♭72135♭7
Box 3 — starts on the 5
EADG121314151617185♭72135♭72
Box 4 — starts on the ♭7
EADG131415161718192021♭72135♭721

The B♭ dominant 9th arpeggio has five playable positions, at frets 3–10, 6–11, 8–15, 12–17 and 13–20.

There are five shapes, and each one starts on a different note of the scale. Once you know one shape you can slide it along the neck, and once you know all five they join up to cover the whole neck.

One climb up the neck

EADG67891011121314151617181235♭71235♭712TAB681081113101215131517

The climb runs from fret 6 to fret 17 and plays twelve 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 three notes on every string. The widest stretch on any one string is five frets.

The words on this page were written with the help of AI and may contain a mistake. Its diagrams are drawn by Everyfret’s own software. How Everyfret is made