Curwen's system was designed to aid in
sight reading of the
stave with its lines and spaces. He adapted it from a number of earlier musical systems, including the Norwich Sol-fa method of
Sarah Ann Glover (1785–1867) of
Norwich. Her Sol-fa system was based on the ancient
gamut; but she omitted the constant recital of the alphabetical names of each note and the arbitrary syllable indicating key relationship, and also the recital of two or more such syllables when the same note was common to as many keys (e.g. C, Fa, Ut, meaning that C is the
subdominant of G and the
tonic of C). The notes were represented by the initials of the seven syllables, still in use in Italy and France as their names. Curwen taught himself to sight-read based on Glover's Norwich Sol-fa, made alterations and improvements, and named his method
Tonic Sol-fa. In the Tonic Sol-fa the seven letters refer to key relationship (relative pitch) and not to absolute pitch. Curwen utilised the first letter (lower case) of each of the solmisation tones (do, re, me, fa, sol, la, ti), and a rhythmic system that used
bar lines (prefixing strong beats), half bar lines (prefixing medium beats), and semicolons (prefixing weak beats) in each measure. Curwen felt the need for a simple way of teaching how to sing by note through his experiences among
Sunday school teachers. Stemming from his religious and social beliefs, Curwen thought that music should be easily accessible to all classes and ages of people. Apart from Glover, similar ideas had been elaborated in France by
Pierre Galin (1786–1821),
Aimé Paris (1798–1866) and
Emile Chevé (1804–1864), whose method of teaching how to read at sight (the
Galin-Paris-Chevé system) also depended on the principle of tonic relationship being taught by the reference of every sound to its tonic, and by the use of a numeric notation. Curwen adapted French time names from Paris'
Langue de durées. ==Curwen's publications==