System of musical notation without staves and notes, invented by John Curwen (1816–1880) in the middle of the 19th century on a basis of the principles of solmization and solfège, and once widely used by choral singers, for whom it simplifies the sight-reading of music.
Tonic sol-fa notation is based on the old syllabic system of Do (Ut), Re, Mi, and so on, and takes the following form: d, r, m, f, s, l, t, the names of the notes being Doh, Ray, Me, Fah, Soh, Lah, Te. The substitution of ‘Te’ for the old ‘Si’ was made to avoid the duplication of the letter ‘s’ in the abbreviations. The range of voices being limited, upper and lower octaves can be sufficiently indicated by a simple stroke placed behind the letters in a higher or lower position, thus: d' represents the note an octave above d, which in turn is an octave above d′. Accidentals (sharps and flats) are indicated by the addition of a letter ‘a’ (ra, ma, etc., or exceptionally ‘u’ for du) for flats and ‘e’ (de, re, etc., or exceptionally ‘y’ for my) for sharps. Accidentals appear comparatively rarely now that the system of the ‘movable Doh’ has been adopted. This is a system of transposition in which everything is sung from a notation that looks as though the music were always in C major or A minor. The actual key is indicated at the beginning of a piece, so that singers know at once, for example, if the composition is in A major, that their d is to be read as A, their r as B, and so on. If the piece modulates to another key, a change is indicated, so that, for instance, d may become temporarily any other note of the scale; but in major keys it will always remain the tonic, in whatever key the music moves, s always the dominant, and f always the sub-dominant. In minor keys I will be the tonic, m the dominant, r the sub-dominant. (A special syllable, ‘ba’, is used for the sharp sixth in the melodic minor scale.) Time divisions are indicated by short bar lines, and there are subdivisions between these. The way in which the notes fill these spaces determines their time-values, though there are special signs for dotted notes, triplets, and others. A blank space means a rest, whereas dashes after a note mean that it is to be held beyond the space it occupies over one or more of the following time-divisions.
The merits of tonic sol-fa have always been subject to Controversy. Its great defect is that it is insufficient for any general study of music as an art and that it is apt to keep choral singers from expanding their musical experience. Its advantages to instrumental players are very slight, since it is not so much easier to learn than staff notation, nor so flexible in picturing the composer's intentions. For choral singers it has not only the merit of simplicity, but the greater one of teaching them a sense of relative pitch as well as removing all difficulties connected with transposition.