Universal key fractions (e.g. an A natural in the scale above becomes ) or, more commonly in written text, by inserting an accidental before the number (e.g. the same note becomes 5 or 4). In music theory aimed towards jazz and popular music, all triads are represented by upper case numerals, followed by a symbol to indicate if it is not a major chord (e.g. "m" for minor or "ø" for half-diminished): When representing the triads rooted in a minor key, accidentals are used to indicate the chromatic alteration from the assumed major key roots indicated by numerals that don't have accidentals:
Key signature require seven flats in their key signature. (The second appearance later in the movement of this same section, a semitone lower, in G minor, uses the correct key signature of two flats.) In principle, any piece can be written with any key signature, using accidentals to correct the pattern of whole and half steps. The purpose of the key signature is to minimize the number of such accidentals required to notate the music. The sequence of sharps or flats in key signatures is generally rigid in modern music notation. This allows musicians to identify the key simply by the number