The notes
- B1
- D♭3
- F♭5
The B diminished arpeggio is B, D, F.
You may also see it called 1 ♭3 ♭5.
On the staff
On a bass staff, the B diminished arpeggio is written B D F.
The solid notes are the B diminished arpeggio. The pale notes are the rest of B locrian, the larger scale it is carved out of, so you can see which notes it leaves out.
Why the B diminished arpeggio has no sharps or flats
- B1
- T+S
- D♭3
- T+S
- F♭5
- 6
- B8
A scale is a pattern of steps, and this one is T+S T+S 6: a tone and a half, a tone and a half, 6, and so on. T+S stands for a tone and a half, which is three semitones. 6 stands for a step of six semitones. The pattern is what gives B diminished its sound, and it stays the same whichever note you start on.
This scale has only three notes, so it does not use every letter. It is B locrian with some notes taken out, and it keeps that scale's spelling exactly.
Every letter already falls where the pattern needs it, so B diminished is written with no sharps or flats at all.
The B diminished arpeggio needs no sharps or flats, because every letter already falls where the T+S T+S 6 pattern of steps needs it.
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
The keyboard shows the same three notes as a shape you can see. The coloured keys are the B diminished arpeggio, the pale keys are the rest of B locrian, and you can click any key to hear it.
B diminished arpeggio on the whole neck
28 notes of the B diminished arpeggio are marked across five strings.
This is every place the notes of the B diminished arpeggio fall on the 5-string bass, with each note's name and its scale degree. The roots are marked so you can find your bearings.
Position by position
The B diminished arpeggio has three playable positions, at frets 3–7, 6–10 and 12–16.
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
The climb runs from fret 0 to fret 7 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 a different number of notes on different strings. The widest stretch on any one string is three frets.