These works continue the line of development that I began with my Tetrachordal Etudes and Pentachordal Etudes, only the pieces are based on trichords (three-note chords). There are only two sets of these, so there are two movements for each set, one of which uses only eight notes while the other uses all twelve. These are simpler than the other works, since trichords and their combinations have fewer notes than tetrachords and pentachprds. Several passages use all seven octaves of the piano and are thus separated into three staves. Melodic lines run throughout the pieces in all octaves, but the harmonies are mainly just trichords. The pieces were composed in the Fall of 2013 and Summer of 2014.