# C-sharp minor
**C-sharp minor** (C♯ minor) is a minor key whose tonic, the first note of its scale, is C sharp, and which is written with a key signature of four sharps: F♯, C♯, G♯, and D♯.[1](https://www.dictionary.com/browse/c-sharp-minor) • [2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) Its natural minor scale runs C♯, D♯, E, F♯, G♯, A, B, one of each letter name, each carrying the sharp the signature gives it.[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) • [3](https://pulse.berklee.edu/scales/c-sharp-minor-scale.html) Its relative major is [E major](https://www.edgepedia.org/e-major), which shares the same four-sharp signature, and its parallel major is C♯ major, which starts on the same note.[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) • [4](https://piano.org/key/c-sharp-minor/)
| Key fact | Detail |
|---|---|
| Key signature | Four sharps: F♯, C♯, G♯, D♯[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) |
| Natural minor scale | C♯, D♯, E, F♯, G♯, A, B[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) |
| Relative major | E major, same key signature[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) |
| Parallel major | C♯ major, same tonic note[4](https://piano.org/key/c-sharp-minor/) |
| Diatonic chords | C♯m (i), D♯dim (ii°), E (III), F♯m (iv), G♯m (v), A (VI), B (VII)[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) |
| Harmonic minor change | Raised 7th degree (B♯) turns the dominant into the major chord G♯[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) |
| Neighbors on the circle of fifths | F♯ minor (a fifth lower) and G♯ minor (a fifth higher)[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) |
| Known repertoire | Beethoven's "Moonlight Sonata" (Op. 27 No. 2) and Rachmaninoff's Prelude Op. 3 No. 2[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) |
## Scales and forms of the key
Minor keys exist in three common forms. The natural minor follows the key signature exactly, so C♯ minor keeps B natural as its 7th degree. The harmonic minor raises the 7th degree by a semitone, turning B into B♯; in C♯ minor this raises the minor v chord G♯m to the major dominant G♯, which is the chord that most strongly pulls the music back to the tonic.[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) Raising the leading tone is a characteristic device of minor keys: in natural minor the 7th degree of the scale is lowered, and it is raised by a semitone in the harmonic minor and in the ascending melodic minor.[5](https://crhs.sch.im/site/uploads/pages/91/_media/20180828_d7577c82/Composition_Booklet_iGCSE.pdf) • [13](https://musictheory.pugetsound.edu/mt21c/MinorScales.html)
Because the signature already puts a sharp on every C, D, F, and G, the notes of the scale each carry the sharp the signature gives them, spelled from the tonic as C♯, D♯, E, F♯, G♯, A, B.[6](https://book-to-articles.onrender.com/tools/accidental-calculator/c-sharp-minor-c) A piece in C♯ minor that uses the harmonic form carries B♯ in the notes even though the written signature shows only four sharps.[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/)
## Chords of the key
One triad sits on each degree of the scale. In the natural minor the chords are:[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/)
- **C♯m** on the tonic (i)
- **D♯dim** on the supertonic (ii°)
- **E** on the mediant (III)
- **F♯m** on the subdominant (iv)
- **G♯m** on the dominant (v)
- **A** on the submediant (VI)
- **B** on the subtonic (VII)
The three principal functions are C♯m as tonic, F♯m as subdominant, and G♯m as dominant.[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) [Roman numerals](https://www.edgepedia.org/roman-numerals) count scale degrees, with uppercase letters marking major chords, lowercase letters marking minor chords, and the small circle marking a diminished chord.[4](https://piano.org/key/c-sharp-minor/)
## How to read and find the signature
A four-sharp signature is read from its last sharp, D♯: a semitone above D♯ is E, the relative major, and the minor key sharing that signature sits a minor third lower, which is C♯.[7](https://chordprogressions.org/keys/c-sharp-minor/) A classroom rule gives the same result for minor keys with sharps generally: the last sharp is a whole step above the key, so counting down a diatonic whole step from the last sharp names the minor key.[8](https://odp.library.tamu.edu/stepstomusictheory/chapter/minor-scales-keys/)
## Relative and parallel keys
A relative pair consists of a major and a minor key with one key signature in common, whereas a parallel pair consists of a major and a minor key whose tonic bears the same note name.[8](https://odp.library.tamu.edu/stepstomusictheory/chapter/minor-scales-keys/) For C♯ minor this gives two distinct relatives. E major, the relative major, shares all seven notes and the four-sharp signature, but its home note is E, three half steps above C♯; the minor key always sits three half steps below its relative major.[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) • [9](https://music-theory.org/keys/relative) C♯ major, the parallel major, keeps C♯ as the tonic but changes the signature, because parallel keys differ by three accidentals: starting from the major key, adding three flats (or the equivalent) produces the parallel minor.[8](https://odp.library.tamu.edu/stepstomusictheory/chapter/minor-scales-keys/)
The same notes that sound bright around E can sound darker around C♯; what differs is the home note the music arrives at.[9](https://music-theory.org/keys/relative) On the circle of fifths, C♯ minor sits between F♯ minor, a fifth lower, and G♯ minor, a fifth higher; these neighbors share all but one note with it.[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) • [10](https://chordwiki.com/keys/c-sharp-minor/)
## How common the key is
Frequency counts from open datasets place C♯ minor among the rarer keys. Within the OpenScore Lieder corpus, a collection of 1,462 songs almost all dating from the 19th century, C♯ minor accounts for 15 songs, which is 1.0% of the corpus overall and 3.3% of the 456 songs judged to be in minor keys; by song count this places the key 21st among the 24 keys. The Mutopia collection gives a matching result, with 7 of 1,974 scores, again 21st of 24.[11](https://musictheoryprint.com/keys/c-sharp-minor) These counts describe that specific repertoire, mostly 19th-century European art songs, not music in general, and such estimates are known to lean toward some keys, so the figures serve as rough comparisons with written music.[11](https://musictheoryprint.com/keys/c-sharp-minor)
The key's best-known works give it a distinct repertoire identity. Beethoven's Piano Sonata Op. 27 No. 2, the "Moonlight Sonata", is in C♯ minor, as is Rachmaninoff's famous Prelude Op. 3 No. 2.[2](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/) [Dictionary](https://www.edgepedia.org/dictionary) usage examples also show Chopin works in the key, including the Fantaisie-Impromptu and a Polonaise in C-sharp minor.[1](https://www.dictionary.com/browse/c-sharp-minor)
## Enharmonic and neighbor keys
Minor keys with sharp signatures run up to seven sharps, and C♯ minor, with four, sits in the middle of that run: G♯ minor has five sharps, and C♯ minor has four.[8](https://odp.library.tamu.edu/stepstomusictheory/chapter/minor-scales-keys/) Even so, the sharp end of the circle has a limit: having reached seven sharps, a further clockwise move would require a double sharp in the key signature, and writers therefore turn instead to the enharmonically equivalent key on the flat side.[12](https://theorypractice.app/learn/key-signature/c-sharp-major) Three minor keys are enharmonically equivalent to flat-side minor keys elsewhere on the circle; E♭ minor, for example, sounds the same as D♯ minor, though E♭ minor is written with flats because its tonic is E♭ and D♯ minor with sharps because its tonic is D♯.[8](https://odp.library.tamu.edu/stepstomusictheory/chapter/minor-scales-keys/)
## References
1. [C-sharp minor, Dictionary.com](https://www.dictionary.com/browse/c-sharp-minor)
2. [C# minor: Key Signature, Scale and Chords, theorie-musik.de](https://www.theorie-musik.de/en/musical-scales/circle-of-fifth/c-sharp-minor/)
3. [C Sharp Minor Scale, Berklee PULSE](https://pulse.berklee.edu/scales/c-sharp-minor-scale.html)
4. [Key of C♯ Minor: Key Signature, Scale, Chords, piano.org](https://piano.org/key/c-sharp-minor/)
5. [Working in a minor key, iGCSE Composition Booklet](https://crhs.sch.im/site/uploads/pages/91/_media/20180828_d7577c82/Composition_Booklet_iGCSE.pdf)
6. [Is C sharp in C♯ minor? Yes — C is C♯, Accidental Calculator](https://book-to-articles.onrender.com/tools/accidental-calculator/c-sharp-minor-c)
7. [C♯ minor — 4 sharps, chords and shapes, chordprogressions.org](https://chordprogressions.org/keys/c-sharp-minor/)
8. [Minor Scales and Keys, Steps to Music Theory, Texas A&M University Libraries](https://odp.library.tamu.edu/stepstomusictheory/chapter/minor-scales-keys/)
9. [Relative and Parallel Keys, music-theory.org](https://music-theory.org/keys/relative)
10. [Key of C♯ minor, ChordWiki](https://chordwiki.com/keys/c-sharp-minor/)
11. [C♯ Minor: Scale, Key Signature and Chords, musictheoryprint.com](https://musictheoryprint.com/keys/c-sharp-minor)
12. [C♯ Major Key Signature, Theory Practice](https://theorypractice.app/learn/key-signature/c-sharp-major)
13. [Minor Scales](https://musictheory.pugetsound.edu/mt21c/MinorScales.html)
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*Topic: Encyclopedia › Arts and culture › Music › Musical practice and theory › Instruments, theory, and world traditions › Pitch, tuning, scales, and musical acoustics*
*Initially written Sep 17, 2026 · Reviewed: Oct 25, 2026 · Edited: Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
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