In music theory, a natural (♮) is a musical symbol that cancels previous key signature or other accidental markings on a note, indicating that the note is at its unaltered pitch.
(HTML : ♮)
The natural symbol can be used as an accidental to cancel sharps or flats on an individual note. It may also be shown in a key signature to indicate that sharps or flats in a previous key signature are cancelled.
A note is referred to as 'natural' when the letter-name note (A, B, C, D, E, F, or G) is not modified by flats or sharps from a key signature or an accidental. These notes are represented by the white keys on the keyboard of a piano or organ.
The keys of A minor or C major and their scales contain all natural notes, whereas other scales and keys have at least one sharp or flat.
F♭, C♭, E♯, B♯, and most notes inflected by double-flats and double-sharps correspond in pitch with natural notes but are regarded as enharmonic equivalents of the natural note.
The natural sign is derived from a square b used to denote B♮ in medieval music (in contrast with the round b denoting B♭, which became the flat symbol). The Unicode character MUSIC NATURAL SIGN '♮' (U+266E) should display as a natural sign. Its HTML entity is ♮.
In musical notation, a natural sign (♮) cancels a flat or sharp from either a preceding note or from the key signature. As a temporary accidental, the natural symbol is written to the left of the note head and applies to any subsequent notes of the same pitch through the remainder of the measure.
Other accidentals such as a flat (♭) or a sharp (♯) are used to alter the pitch of a note with a previous natural sign.
A double natural is a symbol that has two naturals (♮♮). It may be used to cancel a double flat or double sharp but in modern notation a single natural sign (♮) is acceptable.
Similarly, a simple ♭ or ♯ without any natural sign can be used to indicate that a double flat or double sharp has been changed to single(a flat or sharp), but older notation may use ♮♭, ♭♮, ♮♯, or ♯♮ instead.