double sharp

Its key signature has six sharps and one double sharp.

In a case where one needs to cancel a double sharp or double flat, it is acceptable to write a single natural.

An F double sharp is an F sharp that has been sharpened.

G-sharp major (1 double sharp)

The symbol for a double sharp is x and the symbol for a double flat is .

E-sharp minor (1 double sharp)

The symbol he used was similar to the standard symbol for the double sharp, except that it was used in place of a notehead.

Another reason for changing the key signature might be that the music has modulated to a key like G sharp major with eight sharps (including a double sharp).

Sometimes the five "double flat" notes and five "double sharp" notes are replaced by half sharps and half flats, similar to the quarter tone system:

A lower inessential note may or may not be chromatically raised (that is, with a natural, a sharp, or even a double sharp) to make it just one semitone lower than the principal note.

In standard Western equal temperament, the notion of pitch is insensitive to "spelling": the description "G4 double sharp" refers to the same pitch as A4; in other temperaments, these may be distinct pitches.

Conversely, if a double sharp were added to any other note not containing a sharp or flat as indicated by the key signature then the note will be raised two semitones or a whole step with respect to the chromatic scale.

If a bar contains a double sharp or double flat accidental and the composer wishes to denote the same note with only a single sharp or flat, a natural sign traditionally precedes the (single) sharp or flat symbol.

For example, in the aforementioned key signature any note that is not F, C, G, and D will be raised by a whole step or two semitones instead of one, so an A double sharp raises the note A to the enharmonic equivalent of B.

Its key signature has six sharps and one double sharp.

In a case where one needs to cancel a double sharp or double flat, it is acceptable to write a single natural.

An F double sharp is an F sharp that has been sharpened.

G-sharp major (1 double sharp)

The symbol for a double sharp is x and the symbol for a double flat is .

E-sharp minor (1 double sharp)

The symbol he used was similar to the standard symbol for the double sharp, except that it was used in place of a notehead.

Another reason for changing the key signature might be that the music has modulated to a key like G sharp major with eight sharps (including a double sharp).

Sometimes the five "double flat" notes and five "double sharp" notes are replaced by half sharps and half flats, similar to the quarter tone system:

A lower inessential note may or may not be chromatically raised (that is, with a natural, a sharp, or even a double sharp) to make it just one semitone lower than the principal note.

In standard Western equal temperament, the notion of pitch is insensitive to "spelling": the description "G4 double sharp" refers to the same pitch as A4; in other temperaments, these may be distinct pitches.

Conversely, if a double sharp were added to any other note not containing a sharp or flat as indicated by the key signature then the note will be raised two semitones or a whole step with respect to the chromatic scale.

If a bar contains a double sharp or double flat accidental and the composer wishes to denote the same note with only a single sharp or flat, a natural sign traditionally precedes the (single) sharp or flat symbol.

For example, in the aforementioned key signature any note that is not F, C, G, and D will be raised by a whole step or two semitones instead of one, so an A double sharp raises the note A to the enharmonic equivalent of B.