The C♯ 7♭5 Chord Explained
C-sharp dominant seventh flat five is a Dominant chord built from the notes C♯, E♯, G, and B. Its root is C♯, and its interval number formula is 1–3–♭5–♭7. In interval names, that gives you the root, major third, diminished fifth, and minor seventh. You may also see it written as C♯7♭5, C♯7-5, or plain-text spelled C-sharp seven flat five. If you look at the widget above, it can help you picture these chord tones on piano and guitar while you hear how the notes work together. For a beginner, it can also help to learn how the root shapes the chord’s identity in this guide to chord roots.
C♯ 7♭5 Alternate Names
- C♯7♭5
- C♯7-5
- C-sharp seven flat five
C♯ 7♭5 Chord Notes
C♯ 7♭5 Chord Formula
C♯ 7♭5 Chord Notation
How To Use C♯ 7♭5 In Music
Because C♯7♭5 contains a bright major third but an unstable flat fifth, it sounds tense, sharp, and unresolved, which makes it useful for building expectation before another chord arrives. The mood can feel jazzy, dramatic, uneasy, or mysterious, and its effect changes depending on what comes before and after it. For example, it might move to F♯ minor in a progression like I7♭5–iv in C♯, or act as a color-rich secondary dominant in a sequence such as ii–V7♭5–i in F♯ minor, where C♯7♭5 leads toward F♯ minor. In blues, jazz, or theatrical harmony, chords like this are often used for extra pull and color, and you can compare that dominant function with a standard dominant chord.
C♯ 7♭5 Chord Inversions
Another useful idea is inversion, which means rearranging the chord so a note other than C♯ is the lowest pitch. In root position, the notes are C♯–E♯–G–B, but the first inversion places E♯ in the bass, the second inversion places G in the bass, and the third inversion places B in the bass. These inversions do not change the chord’s name, but they do change its weight, balance, and smoothness. A first inversion can sound a bit lighter, while higher-tension bass notes such as G or B can make the chord feel even more unsettled. Musicians use inversions to connect chords more smoothly, create better bass lines, and shape the mood without changing the basic dominant seventh flat five quality.
