Chord library · half-diminished 7th chord
Cm7b5 Chord (C half-diminished 7th): Notes, Guitar, Ukulele and Piano
Cm7b5 chord = C E♭ G♭ B♭. 4 guitar fingerings and 4 ukulele fingerings, checked note by note, with piano keys and staff.
Short answer
The C half-diminished 7th chord (Cm7♭5, also written Cm7b5) has four notes: C, E♭, G♭ and B♭. Above the root C it has a minor third, a diminished fifth and a minor seventh (it is the same chord as B♯ half-diminished 7th, spelled B♯ – D♯ – F♯ – A♯). This page shows 4 guitar fingerings, 4 ukulele fingerings and the keyboard and the staff. It also covers the 2 keys that contain the chord and what the OpenScore Lieder say about it.
- Croot
- E♭3rd
- G♭5th
- B♭7th
- 4notes: C · E♭ · G♭ · B♭
- 4guitar fingerings
- 4ukulele fingerings
- 2of the 24 keys contain this chord
Fingerings: chords-db (MIT licence), checked note by note. Song statistics: OpenScore Lieder, mostly 19th-century art songs, analysed by software; they describe that repertoire, not music in general.
On this page: notes and staff · guitar · ukulele · piano · keys · real songs · look-alikes · questions
The C half-diminished 7th chord: notes, intervals and inversions
A half-diminished 7th chord is built from root + minor third + diminished fifth + minor seventh: a stack of a minor third (3 semitones), a minor third (3) and a major third (4), each placed on top of the one before. On C that gives C, E♭, G♭ and B♭. Each chord tone gets its own letter name (root C, third E, fifth G, seventh B), so the spelling is fixed by the rule, not by taste. Spelling rule: the third is written with the letter E (two letters above C), the fifth with the letter G (four letters above C) and the seventh with the letter B (six letters above C), which is why the chord contains B♭ and not A♯.
Pitch-class numbers (C = 0): 0, 3, 6, 10. The same four pitch classes sound in every octave and in every inversion.
| Chord tone | Note | Interval above the root | Semitones | On the keyboard |
|---|---|---|---|---|
| Root | C | unison | 0 | white key |
| Third | E♭ | minor third | 3 | black key |
| Fifth | G♭ | diminished fifth | 6 | black key |
| Seventh | B♭ | minor seventh | 10 | black key |
C half-diminished 7th on the staff: root position and all three inversions
Treble clef. The notes are the same four each time; only the lowest one changes. Drawn in your browser (VexFlow); the notes are also written out under each staff.
C – E♭ – G♭ – B♭
E♭ – G♭ – B♭ – C
G♭ – B♭ – C – E♭
B♭ – C – E♭ – G♭
An inversion puts another chord tone in the bass. The chord symbol with a slash names the bass note; the last column gives the letter-name distance of each other note above the bass (3 = a third, 5 = a fifth, 7 = a seventh ...).
| Position | Notes, bottom to top | Bass note | Chord symbol | Intervals above the bass |
|---|---|---|---|---|
| Root position | C – E♭ – G♭ – B♭ | C | Cm7♭5 | 7/5/3 |
| First inversion | E♭ – G♭ – B♭ – C | E♭ | Cm7♭5/E♭ | 6/5/3 |
| Second inversion | G♭ – B♭ – C – E♭ | G♭ | Cm7♭5/G♭ | 6/4/3 |
| Third inversion | B♭ – C – E♭ – G♭ | B♭ | Cm7♭5/B♭ | 6/4/2 |
Cm7♭5 on guitar: 4 fingerings
The database lists 4 fingerings for Cm7♭5 on the guitar: 3 barre shapes and 1 closed shape. Strings are drawn left to right in the order E A D G B E (standard tuning, lowest string first). A number inside a dot is the finger (1 = index, 4 = little finger); × marks a string you do not play, ○ an open string, and a bar across the strings is a barre (one finger pressing several strings at the same fret). The letters under each diagram are the note each string sounds, spelled as in the chord (C, E♭, G♭, B♭).
3 of the 4 shapes have the root in the bass; the other has the third or the fifth or the seventh in the bass (a slash chord such as Cm7♭5/G♭).
- Frets × 3 4 3 4 ×
- Fingers – 1 3 2 4 –
- Notes C G♭ B♭ E♭
- Bass C — root position
- Frets × × 4 5 4 6
- Fingers – – 1 2 1 4
- Barre across 3 strings at fret 4
- Notes G♭ C E♭ B♭
- Bass G♭ — second inversion, written Cm7♭5/G♭
- Frets 8 9 10 8 11 8
- Fingers 1 2 3 1 4 1
- Barre across 6 strings at fret 8
- Notes C G♭ C E♭ B♭ C
- Bass C — root position
- Frets × × 10 11 11 11
- Fingers – – 1 3 3 3
- Barre across 3 strings at fret 11
- Notes C G♭ B♭ E♭
- Bass C — root position
Counted from the shapes above.
| Shape | Frets (low string first) | Strings sounding | Bass note | Reads as |
|---|---|---|---|---|
| 1 | × 3 4 3 4 × | 4 | C | Cm7♭5 |
| 2 | × × 4 5 4 6 | 4 | G♭ | Cm7♭5/G♭ |
| 3 | 8 9 10 8 11 8 | 6 | C | Cm7♭5 |
| 4 | × × 10 11 11 11 | 4 | C | Cm7♭5 |
Cm7♭5 on ukulele: 4 fingerings
The database lists 4 fingerings for Cm7♭5 on the ukulele: 2 closed shapes and 2 barre shapes. Strings are drawn left to right in the order G C E A (standard tuning; the G string is tuned high, so the strings do not run from low to high). A number inside a dot is the finger (1 = index, 4 = little finger); × marks a string you do not play, ○ an open string, and a bar across the strings is a barre (one finger pressing several strings at the same fret). The letters under each diagram are the note each string sounds, spelled as in the chord (C, E♭, G♭, B♭).
1 of the 4 shapes has the root in the bass; the other 3 have the third or the fifth or the seventh in the bass (a slash chord such as Cm7♭5/B♭, Cm7♭5/E♭ and Cm7♭5/G♭).
- Frets 3 3 2 3
- Fingers 2 3 1 4
- Notes B♭ E♭ G♭ C
- Bass E♭ — first inversion, written Cm7♭5/E♭
- Frets 5 6 6 6
- Fingers 1 2 3 4
- Notes C G♭ B♭ E♭
- Bass G♭ — second inversion, written Cm7♭5/G♭
- Frets 8 10 8 9
- Fingers 1 3 1 2
- Barre across 3 strings at fret 8
- Notes E♭ B♭ C G♭
- Bass B♭ — third inversion, written Cm7♭5/B♭
- Frets 11 12 11 13
- Fingers 1 2 1 3
- Barre across 3 strings at fret 11
- Notes G♭ C E♭ B♭
- Bass C — root position
Cm7♭5 on the piano keyboard
Press the four keys C, E♭, G♭, B♭ together. The pictures show the same chord in root position and all three inversions, using the voicings of the staves above; the brass keys are the chord tones and the darker one is the root. The keyboards are computed from the spelled notes above, not copied from a database.
C – E♭ – G♭ – B♭
E♭ – G♭ – B♭ – C
G♭ – B♭ – C – E♭
B♭ – C – E♭ – G♭
Key numbers count the 88 keys of a full piano from the lowest A (key 1); middle C is key 40.
| Chord tone | Note | Key colour | Key number (1–88) |
|---|---|---|---|
| Root | C | white | 40 |
| Third | E♭ | black | 43 |
| Fifth | G♭ | black | 46 |
| Seventh | B♭ | black | 50 |
Which keys contain the C half-diminished 7th chord?
The script builds this chord type on every degree of the 24 keys of this site (the scales on the key pages) and keeps the chords whose four pitch classes equal Cm7♭5. Result: 2 of the 24 keys contain it among their own chords.
| Key | Role (Roman numeral) | Written in that key as | How it gets there | Songs in the key (Lieder) | Scores in the key (Mutopia) |
|---|---|---|---|---|---|
| D♭ major | viiø7 | Cm7♭5 | in the key | 49 | 16 |
| Key | Role (Roman numeral) | Written in that key as | How it gets there | Songs in the key (Lieder) | Scores in the key (Mutopia) |
|---|---|---|---|---|---|
| B♭ minor | iiø7 | Cm7♭5 | in the key | 10 | 3 |
The two song columns are the number of OpenScore Lieder songs (of 1,462) and of Mutopia scores whose home key is the key in that row, taken from the key pages. They show how much music is written in the key where the chord lives, not how often the chord itself sounds; that is the next section. In the Lieder the major or minor mode is an estimate, the key signature is exact.
Seventh chords in real music: what the OpenScore Lieder show
The one fact the data gives about seventh chords is how common they are. In the OpenScore Lieder corpus (1,156 art songs, chord labels written by the AugmentedNet software and not checked by a person), 35.2% of the 91,584 chord labels carry a seventh. The analysis stores a chord as a Roman numeral and folds the seventh into the plain chord in its pattern tables, so it cannot say how many of those were half-diminished 7th chords rather than another kind of seventh chord. The songs are mostly 19th-century and say nothing about pop, rock or jazz.
More about the data: Chord progressions in real songs covers the progressions of all 1,156 analysed songs.
Chords easily confused with Cm7♭5
Chords of this library whose pitch classes are exactly those of Cm7♭5. The notes are the same on a keyboard; the name depends on which note is heard as the root, and the spelling follows the key.
| Chord | Its notes | What differs |
|---|---|---|
| E♭ minor 6th | E♭ – G♭ – B♭ – C | root C here, root E♭ there |
Found by comparing the pitch classes of all 168 chords in this library. Sharing three notes is why such chords can stand in for each other in a progression; a chord changes mood or function through the one note that differs.
| Chord | Its notes | Shared with Cm7♭5 | The one note that differs | Root relation |
|---|---|---|---|---|
| C diminished 7th | C – E♭ – G♭ – B𝄫 | C, E♭ and G♭ | B♭ here, B𝄫 there | same root (parallel chord) |
| C minor 7th | C – E♭ – G – B♭ | C, E♭ and B♭ | G♭ here, G there | same root (parallel chord) |
| D♯ diminished 7th | D♯ – F♯ – A – C | D♯, F♯ and C | B♭ here, A there | root a minor third above |
| E♭ major 6th | E♭ – G – B♭ – C | E♭, B♭ and C | G♭ here, G there | root a minor third above |
| E♭ minor 7th | E♭ – G♭ – B♭ – D♭ | E♭, G♭ and B♭ | C here, D♭ there | root a minor third above |
| F dominant 7th suspended 4th | F – B♭ – C – E♭ | B♭, C and E♭ | G♭ here, F there | root a perfect fourth above |
| F♯ diminished 7th | F♯ – A – C – E♭ | F♯, C and E♭ | B♭ here, A there | root 6 semitones above |
| F♯ major 6th | F♯ – A♯ – C♯ – D♯ | F♯, A♯ and D♯ | C here, C♯ there | root 6 semitones above |
| A♭ added 9th | A♭ – C – E♭ – B♭ | C, E♭ and B♭ | G♭ here, A♭ there | root a major third below |
| A♭ dominant 7th | A♭ – C – E♭ – G♭ | C, E♭ and G♭ | B♭ here, A♭ there | root a major third below |
| A diminished 7th | A – C – E♭ – G♭ | C, E♭ and G♭ | B♭ here, A there | root a minor third below |
| B major 7th | B – D♯ – F♯ – A♯ | D♯, F♯ and A♯ | C here, B there | root 11 semitones above |
Enharmonic name. C half-diminished 7th sounds the same as B♯ half-diminished 7th (B♯ – D♯ – F♯ – A♯) on a keyboard. Both spellings are used in practice: choose the one that fits the key of the piece.
Background from Wikipedia: half-diminished 7th chords, chords and inversion
Half-diminished seventh chord
In music theory, the half-diminished seventh chord (also known as a half-diminished chord or a minor seventh flat five chord) is a seventh chord composed of a root note, together with a minor third, a diminished fifth, and a minor seventh (1, ♭3, ♭5, ♭7).
It can be represented by the integer notation {0, 3, 6, 10}.
Source: Wikipedia, “Half-diminished seventh chord” — CC BY-SA 4.0 — text excerpted; see the article for the full text and authors. Revision of 2026-07-04.
Chord
A chord is the simultaneous sound of two or more musical notes. The most common chord has three notes and is known as a triad. Added tone chords, extended chords, and tone clusters can have more than three notes and are common in contemporary classical music and jazz.
An arpeggio is a chord where notes are sounded separately. A series of chords is sometimes called a chord progression. There are several ways to notate chords including figured bass, Roman numerals, the Nashville Number System, and alphabetical chord notation.
Source: Wikipedia, “Chord (music)” — CC BY-SA 4.0 — text excerpted; see the article for the full text and authors. Revision of 2026-04-05.
Inversion: root position and inverted chords
Root position and inverted chords
A chord is in root position if its root is the lowest note. This is sometimes known as the parent chord of its inversions. For example, the root of a C-major triad is C, so a C-major triad will be in root position if C is the lowest note and its third and fifth (E and G, respectively) are above it – or, on occasion, do not sound at all.
In an inverted chord, the root is not the lowest note. The inversions are numbered in the order their lowest notes appear in a close root-position chord (from bottom to top).
- In the first inversion, the lowest note is E – the third of the triad – with the fifth and the root stacked above it (the root now shifted an octave higher), forming the intervals of a minor third and a minor sixth above the inverted bass of E, respectively.
- In the second inversion, the lowest note is G – the fifth of the triad – with the root and the third above it (both again shifted an octave higher), forming a fourth and a sixth above the (inverted) bass of G, respectively.
Source: Wikipedia, “Inversion (music)” — CC BY-SA 4.0 — text excerpted; see the article for the full text and authors. Revision of 2026-07-03.
Practise the C half-diminished 7th chord
Pages on this site that go with this chord. The worksheet counts are read from the worksheet pages themselves.
Charts and practice
- Guitar chord chart (printable) the common open and barre chords of all 12 keys on one sheet you can print
- Ukulele chord chart (printable) the same for GCEA ukulele
- Piano chord chart (printable) chords and inversions on the keyboard, all 12 keys
- Interval chart see the intervals above the root: minor third, diminished fifth and minor seventh
- Treble clef note names find C, E♭, G♭ and B♭ on the staff
- Staff paper write Cm7♭5 and its inversions by hand
- Key signatures chart see which keys carry the sharps or flats in Cm7♭5
- Circle of fifths the keys that contain Cm7♭5 sit close together on the circle
- Chord identification practice name chords from the notes
- Interval identification practice train the ear and eye for thirds and fifths
Worksheets
- Seventh chord identification worksheets (root position, easy) printable worksheet sets
- Seventh chord writing worksheets (root position, easy) printable worksheet sets
C half-diminished 7th: questions people ask
What notes are in the C half-diminished 7th chord?
The C half-diminished 7th chord (Cm7♭5) has four notes: C, E♭, G♭, B♭. They are the root C, a minor third (E♭), a diminished fifth (G♭) and a minor seventh (B♭). In root position the notes are stacked as a minor third (3 semitones), a minor third (3) and a major third (4), each placed on top of the one before.
How do you play Cm7♭5 on guitar?
The chords-db database lists 4 guitar fingerings for Cm7♭5 that passed the checks. The first one (closed shape, frets 3–4) uses frets x 3 4 3 4 x from the lowest string, fingers – 1 3 2 4 –; it sounds C G♭ B♭ E♭ with C in the bass. All of them are on this page as diagrams, with finger numbers and the note under every string.
How do you play Cm7♭5 on ukulele or piano?
On a standard GCEA ukulele the first listed fingering is frets 3 3 2 3 (strings G, C, E, A), sounding B♭ E♭ G♭ C; 4 fingerings are shown in all. On piano press C, E♭, G♭ and B♭ together; the inversions are Cm7♭5/E♭, Cm7♭5/G♭ and Cm7♭5/B♭.
Is C half-diminished 7th the same as B♯ half-diminished 7th?
They sound the same: C half-diminished 7th is spelled C – E♭ – G♭ – B♭ and B♯ half-diminished 7th is spelled B♯ – D♯ – F♯ – A♯, and each pair of names is the same key on the piano. The name that is used depends on the key of the piece, because every letter of the scale has to be used once.
Which keys contain the C half-diminished 7th chord?
It is one of the chords of 2 of the 24 keys: D♭ major (viiø7) and B♭ minor (iiø7).
How common are seventh chords in real music?
In the OpenScore Lieder (19th-century art songs analysed by software, not checked by a person) 35.2% of the chord labels carry a seventh. The analysis does not separate the kinds of seventh chord, and the data say nothing about pop or jazz.
How this page was made
- Note names. Computed from the root and the interval pattern with the rule “one letter name per chord tone” (the same code that spells the scales on the key pages), then checked: letters, semitone pattern, no double accidentals.
- Fingerings. Every position comes from chords-db; the script recomputes the sounding pitch of each string in standard tuning and stops the build unless all of them are notes of this chord.
- Roles in keys. The chord type is built on every degree of the 24 key scales used on the key pages; a chord counts when its pitch classes equal this chord's.
- Statistics. The only song statistic on this page is the share of chord labels with a seventh, read from the OpenScore Lieder analysis; counts of songs per key come from the key pages.
- Independent check. A separate test (tests/chordlib/verify-tonal.test.mjs) re-derives the notes of every page with the tonal library and compares notes, staff voicings, keyboard voicings and every fingering.
Data used
- chords-db — guitar and ukulele fingerings, piano note lists (version 0.6.0) MIT
- OpenScore Lieder, automatic harmonic analyses — chord-use shares, chord-to-chord transitions and per-key progression counts CC0 1.0
- Wikipedia — excerpts from Half-diminished seventh chord, Chord (music) and Inversion (music), snapshot 2026-07-01 CC BY-SA 4.0
- The Mutopia Project — number of scores in each key per-piece licences; counts only
What this page cannot tell you
- The fingerings are one community-maintained database's choices; many other fingerings exist, and a good player will voice the chord to suit the music.
- Chord labels in the Lieder are software output that nobody has checked, for 19th-century art songs. Percentages show the repertoire, not pop or jazz.
- Sevenths and inversions are folded into the plain chord in the Lieder statistics, so they cannot tell a root-position triad from a first inversion.
- Roles in keys are counted for the 24 keys on this site and for major, natural and harmonic minor only; other scales (melodic minor, modes) are not searched, and only the third, fourth, sixth and seventh degrees of the parallel minor are borrowed.
Checks run each time this page is rebuilt
- spelling: one letter name per chord tone (C–E–G–B), semitone pattern 3+3+4
- staff and keyboard: 4 voicings, every note is a chord tone, the lowest note of voicing n is chord tone n
- drawings read back from the finished SVG: every dot, open ring, cross, barre and note letter equals the data; the keyboards highlight exactly the chord tones
- guitar: 4 shapes, ukulele: 4 shapes, 34 sounding strings in total, every one a chord tone; computed midi = database midi; barres playable
chords-db licence (MIT) — fingering data used on this page
The guitar and ukulele fingerings come from chords-db (version 0.6.0). Its licence text, which must travel with the data, is:
MIT License Copyright (c) 2016 David Rubert Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Data: chords-db (David Rubert) (MIT); OpenScore Lieder Corpus (CC0 1.0); Wikipedia (CC BY-SA 4.0). Guitar and ukulele fingerings: chords-db, Copyright (c) 2016 David Rubert, MIT licence (full text above). Wikipedia excerpts are under CC BY-SA 4.0 with the article named at each excerpt. Computed for this site on 2026-10-08. Licences and credits for everything used on this site are on the credits page.