Musical note commonly), a double sharp sign on a key signature with a single sharp indicates only a double sharp, not a triple sharp. Assuming enharmonicity, many accidentals will create equivalences between pitches that are written differently. For instance, raising the note B to B is equal to the note C. Assuming all such equivalences, the complete chromatic scale adds five additional pitch classes to the original seven lettered notes for a total of 12 (the 13th note completing the octave), each separated by a half-step. Notes that belong to the diatonic scale relevant in the context are sometimes called "diatonic notes";
Heptatonic scale Heptatonic scale A heptatonic scale is a musical scale that has seven pitches per octave. Examples include the "major scale" or "minor scale"; e.g., in C major: C D E F G A B C—and in the relative minor, A minor, natural minor: A B C D E F G A; the "melodic minor scale", A B C D E FGA ascending, A G F E D C B A descending; the "harmonic minor scale", A B C D E F GA; and a scale variously known as the "Byzantine", and "Hungarian", scale, C D E F G A B