Quite often people refer to an author’s best work as their ‘magnum opus’ or greatest, biggest, and best work.

Its etymology is as you might expect is from the same Latin word meaning ‘a work, labor or exertion’. The abbreviation, often written as ‘Op.’ refers to this word that means work. You will notice that the word ‘opus’ is used in the context of the composer’s works or compositions.

This is because many of Beethoven’s works had no catalog number when they were published leading to some significant confusion about when they were written. This gave rise to catalogs of composers’ works having a variety of pre-cursors like ‘K’ for Mozart’s compositions, ‘BWV’ for JS Bach’s and Beethoven commonly, ‘WoO’ meaning ‘works without opus number’. For many, this was arranged posthumously, and not always with a great degree of accuracy. Keeping composition work in order and cataloged was not something many composers took time to do. Composers are not always known for their organizational skills.

What is the meaning of op