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:
Pitch pipe marked the notes of either the chromatic scale or the diatonic scale, and by setting it to the correct position, the indicated note will be produced when the instrument is blown. Pitch pipes come in all sorts of shapes and sizes. Pitch pipes of this sort were most often used in the 18th and 19th centuries in churches which had no organ to give the opening note of a hymn. They are now quite rare, and hardly ever used for what they were intended, but may still be used as an alternative to a tuning fork. They are also useful