An assessment of the standard voice instructor or performer collection of printed music would likely reveal numerous operatic repertoire volumes in anthology format appropriated to the primary four voice categories. However, thorough investigation divulges little in comparable printed material accessible to the countertenor. This scarcity of systemized collections is especially evident in the territory of comprehensive countertenor operatic repertoire. This project fills that present void by creating a compilation of sixteen countertenor arias drawn from various styles and historical periods for suggested application in studio instruction and performance. Perhaps, a more meaningful project intent is the presentation of a beneficial graded literature continuum resource for the studio teacher who instructs a countertenor in various stages of vocal development. For this purpose, each of the 16 arias is categorized into four difficulty levels based on considerations of range, tessitura, coloratura demands, rhythm, sustained phrase length, tonality, melodic considerations/overall musical difficulty, accompaniment support, and ornamentation requirements. The project also addresses common issues of pedagogy and ornamentation for voice teacher consideration when instructing a developing countertenor.