Colonial American Protestants had inherited certain British features, like language and currency, during the time of British colonialism in what would become the United States. Americans also acquired the English system of solmization, in which a distinct syllable is attributed to each note of a musical scale. In contrast to the Italian solfege system, which makes use of seven syllables (do, re, mi, fa, sol, la, and ti), with one syllable corresponding to each respective degree of the diatonic major scale, the English system uses only four syllables (fa, sol, la, and mi). Its diatonic major scale is sung fa-sol-la-fa-sol-la-mi-fa, with the tonic, or first degree of the scale, repeated at the top. The intervals between the fa, sol, and la are the same the first and second times they appear in the scale. Between the first and second iterations, the series of notes is offset by a half- step. After the second iteration, leading up to a new octave, a mi is added. The natural minor scale uses the same syllables and intervals but begins on the sixth degree la. One fa in the scale is always a perfect fourth or fifth away from the other. The same is true of a sol or a la. Half steps and whole steps are expressed very clearly with only four syllables. Any note that appears directly below fa, whether it is a la or a mi, is a half step away, and any other move between two adjacent notes covers the distance of a whole step.
The next logical step was to create a system that would connect the aural and the visual. In the four-shape system most commonly attributed to William Little and William Smith, a right-sided triangle corresponds with the syllable fa; an oval with the syllable sol; a rectangle with la; and a diamond corresponds with the syllable mi. Little and Smith’s shaped notes would provide singers with a better understanding how the syllables relate to the intervals between them. No longer would a singer need to decipher key signatures and figure out which of the many round notes corresponded to which syllable. The shapes, readily available to further reinforce the relationships between syllables, assist in sight-reading music. This is the system used in The Sacred Harp.