Santini developed a system of composition using 21-tone rows. This system is similar to the more familiar 12-tone system of serial composition, but the rows Santini used as the basis of his 21-tone compositions also include all alternative enharmonic spellings for each note in the chromatic scale (except the notes D, G, and A, which have no enharmonic spellings). Thus, the available tones for a 21-tone row would include B-sharp, C, C-sharp, D-flat, D, D-sharp, E-flat, E, F-flat, E-sharp, F, F-sharp, G-flat, G, G-sharp, A-flat, A, A-sharp, B-flat, B, and C-flat. In order to generate 21-tone rows, Santini utilized a specially printed deck of cards (each card representing one of the aforementioned pitches), "dealing" himself rows until he found the row or rows he wished to use as the basis for a particular composition.