opusculum

Opusculum—which is often used in its plural form opuscula—comes from Latin, where it serves as the diminutive form of the noun opus, meaning "work." In English, opus can refer to any literary or artistic work, though it often specifically refers to a musical piece. Being a diminutive of opus, opusculum logically refers to a short or minor work. Unlike its more famous relation, however, opusculum is most often used for literary works. The Latin plural of opus is opera, which gave us (via Italian) the word we know for a musical production consisting primarily of vocal pieces performed with orchestral accompaniment.