The interval between G and A is a whole step because it consists of two half steps (G to A flat and A flat to A).

Typical system

• 1: G♮, G♯, G♯ (the sharp carries over)
• 2: G♮ (with courtesy accidental), G♭, G♭ (the flat carries over)
• 3: G♭ (which is tied from the previous note), G♯, G♮ (the natural sign cancels the sharp sign)

Musical notes are written on a staff. A staff is made up of five horizontal lines and the four spaces between the lines. The vertical lines on the staff are called bars. The space between two bar lines is called a measure.

Accidentals can be sharp, flat, or natural notes depending on the context of the key. For example, if we’re in the key signature of G major which features the notes G, A, B, C, D, E and F#, any use of an F natural note would be considered to be an accidental.

For flat keys: Find the second-to-last flat. This is your major key. Try the flat-key example below. Reading from left to right, the flats are Bb, Eb, Ab, Db, and Gb.

Key signature, in musical notation, the arrangement of sharp or flat signs on particular lines and spaces of a musical staff to indicate that the corresponding notes, in every octave, are to be consistently raised (by sharps) or lowered (by flats) from their natural pitches.

To find the name of a key signature with sharps, look at the sharp farthest to the right. The key signature is the note a half step above that last sharp. Key signatures can specify major or minor keys. To determine the name of a minor key, find the name of the key in major and then count backwards three half steps.

A key signature is a visual symbol, printed on a musical staff, that indicates what key a section of music is written in. Key signatures are represented by using accidentals—better known as sharps and flats. The number of sharps or flats indicated in the key signature will tell the player what key the music is in.

In Western musical notation, a key signature is a set of sharp (♯), flat (♭), or rarely, natural (♮) symbols placed on the staff at the beginning of a section of music. The initial key signature in a piece is placed immediately after the clef at the beginning of the first line.