Other forms: opuscules
An opuscule is a small or minor work, such as a short piece of writing or a brief musical composition. While creating a great work of literature might be the dream of some authors, others are happy to publish even an opuscule.
An opus is "a significant work or creation." Adding magnum ("great") before opus gives us magnum opus ("great work"), used for a person's greatest masterpiece. Adding the diminutive -cule ("small, little") to opus gives us opuscule, meaning "a small or minor work." An opuscule might be a short essay, a brief musical sketch, or a minor scholarly tract. An author might modestly refer to their own book as an opuscule to avoid sounding boastful. But the word is most commonly used for shorter literary, musical, and scholarly compositions.