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";
Chord-scale system the system. For example, Russell associated the C major chord with the lydian scale, while teachers including John Mehegan, David Baker, and Mark Levine teach the major scale as the best match for a C major chord. Miles Davis's "Lydian Chromatic Concept"-influenced first modal jazz album "Kind of Blue", is often given as an example of chord-scale relationships in practice. The chord-scale system provides familiarity with typical chord progressions, technical facility from practicing scales and chord arpeggios, and generally succeeds in reducing "clams", or notes heard as mistakes (through providing note-choice possibilities for the chords of progressions), and building "chops",