Key signatures: G major and F major
G major's key signature has one sharp, F sharp. F major's has one flat, B flat. The signature applies in every octave: play every F as F sharp in G major and every B as B flat in F major, unless an accidental changes it. These signatures also belong to E minor and D minor, respectively. Look at the key signature before the first note, every time.
Practice G and F major in Unit 10New to Octotune? Start at Unit 1, or take a short placement test to reach a later unit.
G and F major key signature charts
What key has F sharp?
If F sharp is the only sharp in the key signature, the key is G major or E minor. G major has one sharp. Seeing an F sharp beside a single note does not identify the key on its own: it could be an accidental or belong to another key signature.
F sharp major is a different key. Its signature has six sharps: F, C, G, D, A and E. Its scale is F♯ G♯ A♯ B C♯ D♯ E♯ F♯. E sharp is played on the same piano key as F natural, but is spelled E sharp to keep one of each letter in the scale.
| Key | Signature | Notes in the major scale |
|---|---|---|
| G major | One sharp: F♯ | G A B C D E F♯ G |
| F major | One flat: B♭ | F G A B♭ C D E F |
| F sharp major | Six sharps: F♯ C♯ G♯ D♯ A♯ E♯ | F♯ G♯ A♯ B C♯ D♯ E♯ F♯ |
F major uses B flat, not F flat. F flat is a different note, played on the same piano key as E natural; it does not belong to the F major signature. The rest of this guide teaches G and F major, the two keys introduced in Octotune's beginner path.
G major: one sharp
The G major key signature is a single sharp (♯) drawn on an F:
- Treble staff: on the top line, F5.
- Bass staff: on the fourth line, F3, between the bass clef's dots.
It means every F is F sharp: the F on the top line, the F in the bottom space, the Fs above and below the staff. F sharp is the black key just below G, the first of a group of three black keys.
The G major scale is G A B C D E F♯ G. Only the F changes.
F major: one flat
The F major key signature is a single flat (♭) drawn on a B:
- Treble staff: on the middle line, B4.
- Bass staff: on the second line, B2.
It means every B is B flat. B flat is the black key just below B, the last of a group of three black keys.
The F major scale is F G A B♭ C D E F. Only the B changes.
Reading notes in a key
- A sharp or flat doesn't move the note on the staff. F sharp sits on the same line or space as F; it is played on a different key. The staff says which letter; the key signature says which key of that letter.
- The signature is not repeated beside each note. That is its whole point: it is written once, at the start of each line.
- A natural sign (♮) beside a note cancels the key signature for that note, until the end of the measure.
- An accidental (a sharp, flat or natural written beside a note) lasts until the end of its measure, on that line or space.
How the hand finds the black key
In G major, the right hand often plays in a G position: thumb on G, fingers on A, B, C, D. F sharp is then just below the thumb, or reached by the fourth finger from higher up. In F major, B flat falls under the fourth finger in an F position (thumb on F: F G A B♭ C).
Major or minor?
Every key signature is shared by a major and a minor key. One sharp is G major or E minor; one flat is F major or D minor. The music itself tells you which: a piece in E minor usually begins or ends on E and often has D sharps written in. Octotune's path stays with the major keys.
Common mistakes
- Playing F natural in G major. The most common mistake of all: the sharp isn't printed next to the note. Look at the key signature before you start.
- Thinking the sharp only applies to one F. It applies to every F, in every octave.
- Thinking a sharp moves the note on the page. Same line, different key.
- Forgetting the bass clef. The left hand's Fs are sharp in G major too.
How to practice
- Circle every F on a page of music in G, or every B in F, before you play.
- Play the scales hands separately: G major with its F sharp, F major with its B flat.
- Find F sharp in every octave, then B flat in every octave.
- Play a simple piece in each key. The Minuet in G (the one long credited to Bach, now to Christian Petzold) is the classic for G major; Yankee Doodle works well for F.
How Octotune helps
Unit 10 of Octotune's adult path is keys: a concept card on key signatures, then F sharp met in both clefs, cards and pages written in G, the Minuet in G and Schumann's music; then B flat, pages in F, Yankee Doodle and The Happy Farmer. Note cards in a key only ever show notes that belong to that key. In the app's coach, a black key is spelled for the key you are in: B flat in F major, never A sharp. Open Octotune.
Next: Triads and the I, IV and V chords.
Questions
How many sharps are in G major?
One: F sharp. The signature also belongs to E minor. Every F is sharp in every octave unless an accidental changes it.
Is a key signature with F sharp the same as F sharp major?
No. A signature with only F sharp is G major or E minor. F sharp major has six sharps: F, C, G, D, A and E. A single F sharp note cannot tell you the key by itself.
What key has one sharp?
G major (and its relative minor, E minor). The sharp is F sharp, drawn on the top line of the treble staff and the fourth line of the bass staff, and it applies to every F in every octave.
What key has one flat?
F major (and its relative minor, D minor). The flat is B flat, drawn on the middle line of the treble staff and the second line of the bass staff, and it applies to every B.
Does a key signature apply to every octave?
Yes. The sharp in G major is drawn on one F, but it means every F on the keyboard, high and low, for the whole piece, unless a natural sign cancels it.
Where is F sharp on the piano?
The black key just below G: the first of a group of three black keys.