twelvenotes
twelvenotes is a term sometimes used to refer to the twelve distinct pitches used in Western music within a single octave. These pitches are based on the chromatic scale. Starting from any given note, the twelve notes are reached by ascending or descending by half steps. The names of these notes in the Western system are typically A, A#, B, C, C#, D, D#, E, F, F#, G, and G#. Alternatively, using the sharp symbol '#' for ascending half steps, the sequence is A, Bb, B, C, Db, D, Eb, E, F, Gb, G, Ab. The relationship between these notes is based on mathematical ratios, particularly the octave, which represents a doubling of frequency, and the perfect fifth, with a ratio of 3:2. The development of this system, known as equal temperament, allows for music to be played in any key without significant tuning issues, though it involves slight compromises in the purity of some intervals compared to older tuning systems. The concept of twelve notes forms the basis of scales, chords, and harmony in much of the music composed and performed globally.