The methods of writing down mus. so that it can be performed. These are devices for which the human being long felt no need, and although every race has its mus. they are still unknown to the larger part of the world's population. They are apparently purely European in origin and even in Europe thousands of tunes existed which were transmitted by one generation to another without achieving the dignity of being recorded on paper until the folk‐song collectors came on to the scene.
The naming of notes by letters of the alphabet goes back as far as the Ancient Greeks; the Romans also possessed an alphabetical system. In both cases, however, this nomenclature served rather the purposes of scientific discussion than those of performance.
An early (7th‐cent.) system of notation was that of neum(e)s. Our conventional signs for the turn and the trill are derived from details of neum notation. The present exactitude in pitch indication has been effected by adding to the one line of the early neum notation. Plainsong now uses a staff of 4 lines, and other mus. one of 5 lines. The clef derives from neum notation: attached to the Staff it fixes the pitch of one of its lines as middle C or some other note, from which all the others may be deduced.
Proportional notation of an exact character (i.e. as to the time values) began in the 10th cent. when the primitive developments of polyphony brought about its necessity. Definite notes, of different shapes according to their intended proportionate length, were devised, from which our present series of semibreve (whole‐note), minim (half‐note), etc. is derived. Bar lines became common only during the 16th and 17th cents. (the earliest use dates from 1448): they were at first casually drawn as aids to the eye—the idea of making them of equal time‐value coming later. They first arose in choral scoring to demonstrate the coincidence of the different vv., and were originally not present in the independent vocal parts for the use of singers.
Adjustments to and changes in traditional staff notation have increased in the 20th cent., particularly since c.1950 when total serialism, aleatory procedures, etc. have required a parallel development of notational signs, resulting in some confusion where individual composers have devised their own methods which may use terms employed by another composer for a different effect. Some mus. cannot be written at all in conventional notation. The subject is too large for more than an outline to be given here, but some of the changes can be mentioned briefly.
With the arrival of atonal and 12‐note mus., conventional pitch notation, with its selection of accidentals, tended to become unworkable, but no new system has been generally adopted, and makeshift adaptation of conventional methods has been favoured by performers. Systems of microtonal notation devised by A. Hába and J. Carillo have not lasted.
Traditional notation is little use in pulseless mus. and in mus. in which different and often complicated rhythms progress simultaneously at different speeds. To cope with notating these durations, proportionate notation has been employed, whereby durational proportions are transmuted into the graphic equivalent of notes spaced out horizontally along the staff according to their durations.