What notes are in an F♯ half-diminished chord?

F♯ half-diminished contains four notes: F♯ (root), A (minor third), C (diminished fifth), and E (minor seventh).

What is the Tristan chord?

The famous opening chord of Wagner's Tristan und Isolde — F-B-D♯-G♯ in his actual notation, which is enharmonically a half-diminished sonority. It's often analysed as F♯m7♭5 reinterpreted enharmonically. The chord's ambiguous resolution defined late-Romantic harmonic language.

How does F♯m7♭5 resolve?

In E minor: F♯m7♭5 → B7 → Em. The chord prepares the dominant B7, which then resolves to the tonic Em. In Wagner's Tristan, the chord deliberately doesn't resolve in the standard way — it sets up an entire opera of harmonic suspense.

Where does F♯m7♭5 appear in music?

Wagner's Tristan und Isolde (the most famous appearance), every E-minor jazz standard, and countless classical E-minor cadences. It's one of the most-studied chords in Western music history.

F# half-diminished chord — notes, intervals, and practice

F♯ half-diminished (F♯m7♭5 or F♯ø) — F♯, A, C, E — is the iiø7 of E minor and the famous "Tristan chord" (Wagner's opening to Tristan und Isolde, the chord that arguably launched late-Romantic chromaticism). The chord's harmonic ambiguity made it a touchstone for everything from Wagner to Debussy.

Intervals

The F# half-diminished chord stacks two thirds on the root. Each interval and its size in semitones:

F#→Aminor 3rd3 semitones
A→Cminor 3rd3 semitones
C→Emajor 3rd4 semitones

On the keyboard

Each note of the F# half-diminished chord highlighted on a piano. Pitch class is what matters — any octave works.

On the guitar

One voicing of the F# half-diminished chord on a six-string guitar fretboard.

Common mistakes

F♯m7♭5 has F♯-A-C-E. The seventh E is natural (a minor 7th from F♯), not E♯. The flat fifth C is natural too; replacing it with C♯ makes F♯m7. The famous Tristan chord context uses this exact spelling — Wagner's opening note B in the bass plus F♯, A, C, E above creates a dense, ambiguous half-diminished colour that resolves only after several measures of suspense.

In context

F♯m7♭5 → B7 → Em is the ii–V–i in E minor — used in every E-minor jazz standard. In Wagner's Tristan, the famous opening F♯m7♭5 lingers and resolves through chromatic voice-leading to E7 (rather than the expected B7), launching an entire era of harmonic ambiguity.

Drill it

The F# half-diminished chord is one of 48 in the Chord Trainer. Open the full trainer to practice it alongside related chords with timing and best-time tracking.

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Frequently asked

What notes are in an F♯ half-diminished chord?: F♯ half-diminished contains four notes: F♯ (root), A (minor third), C (diminished fifth), and E (minor seventh).
What is the Tristan chord?: The famous opening chord of Wagner's Tristan und Isolde — F-B-D♯-G♯ in his actual notation, which is enharmonically a half-diminished sonority. It's often analysed as F♯m7♭5 reinterpreted enharmonically. The chord's ambiguous resolution defined late-Romantic harmonic language.
How does F♯m7♭5 resolve?: In E minor: F♯m7♭5 → B7 → Em. The chord prepares the dominant B7, which then resolves to the tonic Em. In Wagner's Tristan, the chord deliberately doesn't resolve in the standard way — it sets up an entire opera of harmonic suspense.
Where does F♯m7♭5 appear in music?: Wagner's Tristan und Isolde (the most famous appearance), every E-minor jazz standard, and countless classical E-minor cadences. It's one of the most-studied chords in Western music history.