3. The abbreviation "Op." that follows the titles of many pieces of music is short for opus, the Latin word that means "work" (as in a work of art). What does the designation "woo" mean?
From Quiz Thematic Catalogues: What's in an Opus Number?
Answer:
It means "without opus"
"Woo" actually comes from the German phrase "Werke ohne Opuszahl," and translates handily to the English "without opus." The Latin plural of opus is opera, so to prevent confusion with the musical genre, music buffs use the contrived plural "opuses." Opuses is abbreviated Opp.
Barry Brook is a leading authority on thematic catalogues, and I wish to credit him here, as I learned many of the details for this quiz from his book (co-authored with Richard Viano) "Thematic Catalogues in Music: An Annotated Bibliography (2nd edition)" (Stuyvestant (NY): Pendragon Press, 1997). Grove Music Online was also a valuable resource.
The opus number and the thematic catalogue have a long history. Operas and other stage works seldom receive opus numbers, since their titles tend to distinguish them, but pieces whose titles are more generic ("Symphony" or "Sonata," for instance) need something else to set them apart (besides their key, as composers may write two or more pieces in the same genre with the same key).
Before Beethoven first broke the ground for composers to systematically group their own pieces into chronological opus numbers, opus numbers were assigned by publishers. As tools for musicologists to establish the chronology and authenticity of composers' output, publishers' opus numbers are often insufficient, as many composers can have multiple publishers, publish their works in a different order than they were written, and choose not to publish some works at all. To solve this problem, scholars began to research and formally organize the works of composers, and the thematic catalog was born. In fact, Brook says, the emergence of thematic catalogues coincided with the development of musicology as a discipline.
A thematic catalogue may include for each piece listed: title, key, genre, instrumentation, publishing data, date and location of composition (if known), information about revisions, incipit(s), and other data. An incipit is a musical notation of a work's (or movement's) theme or first several bars, and serves to identify a piece as being unique. Catalogues may be arranged chronologically, by genre, key, or otherwise.
Köchel's 1851 catalogue of Mozart's music is a significant early attempt at an annotated scholarly inventory of a composer's output. The tradition has continued ever since, with a practical explosion of cataloguing projects that began in the 1950's. Now, composers often refer to their own works by title and the year they were completed.
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