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 musical "Seussical" by Flaherty and Ahrens also has several songs written in these extreme keys. Key signatures can be further extended through double sharps and double flats (for example, a piece in the key of G major can be expressed with a double sharp on F and six sharps on the other six pitches). As with the seven-sharp and seven-flat examples, it is rarely necessary to express music in such keys when simpler enharmonic examples can instead be used (in the case of G, the same passage could be expressed in A with only four flats). The key signature may