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";
Jazz scale Jazz scale A jazz scale is any musical scale used in jazz. Many "jazz scales" are common scales drawn from Western European classical music, including the diatonic, whole-tone, octatonic (or diminished), and the modes of the ascending melodic minor. All of these scales were commonly used by late nineteenth and early twentieth-century composers such as Rimsky-Korsakov, Debussy, Ravel and Stravinsky, often in ways that directly anticipate jazz practice. Some jazz scales, such as the bebop scales, add additional chromatic passing tones to the familiar diatonic scales. One important feature of jazz is what theorists call "the principles of chord-scale compatibility":