F-flat major

F♭ major

120px
Relative key	D♭ minor enharmonic: C♯ minor
Parallel key	F♭ minor enharmonic: E minor
Dominant key	C♭ major enharmonic: B major
Subdominant	B major enharmonic: A major
Enharmonic	E major
Component pitches
F♭, G♭, A♭, B, C♭, D♭, E♭, F♭

F-flat major is a major scale based on F-flat, consisting of the pitches F♭, G♭, A♭, B, C♭, D♭, and E♭. Its key signature has six flats and one double flat.

Its relative minor is D-flat minor, usually replaced by C-sharp minor (see reason below) and its parallel minor is F-flat minor, usually replaced by E minor, since F-flat minor's four double-flats make it generally impractical to use.

Part of Richard Strauss' Metamorphosen uses F-flat major, which one commentator has called "a bitter enharmonic parody" of the earlier manifestations of E major in the piece.

For clarity and simplicitly, F-flat major is usually notated as its enharmonic equivalent of E major, because of E major only having 4 sharps as opposed to F-flat major's 8 flats (including the B-double-flat).

A well-known example can be found in Beethoven's Piano Sonata No. 31, op. 110. In the first movement's exposition, the transitional passage between the first and second subjects consists of arpeggiated figuration beginning in A-flat major and modulating to the dominant key of E-flat major. In the recapitulation, the key for this passage is changed to bring the second subject back in A-flat major: the transitional passage appears in a key that would theoretically be F-flat major, but which is notated in E major, presumably because Beethoven judged this easier to read - this key being a major third below the key of the earlier appearance of this passage.

Another example of F-flat major being notated as E major can be found in the Adagio of Haydn's Trio No. 27 in A-flat major. The Finale of Bruckner's Symphony No. 4 employs enharmonic E for F-flat, but its Coda employs F-flat directly, with a phrygian cadence through F-flat onto the tonic.