In New England before 1800 a revolutionary method of teaching singing to rural America was spread by itinerant "singing school" teachers who used song books printed in an unusual musical notation: different tones were represented by different geometric shapes. Usually in the evenings, when students could congregate, the singing teacher would stay no more than one month in any community- but, lessons of approximately three hours duration were held each evening. It was the beginning of harmonic group singing in this nation, for the songs in the new "song books" were usually printed in four-part harmony. Such singing, usually unaccompanied, was brought with them by the settlers as the frontier moved south and westward.

The original shape-note notation had four different characters, one each to represent the pitches fa, sol, la, and mi, so that one would memorize a shape together with its relative pitch. Eventually, by the late 1800s through European influence, the seven character notation- do, re, mi, fa, sol, la, ti - became dominant and the method of reading music became known as "do re mi" singing.