Opus number facts for kids

An opus (pronounced OH-pus) is a special word used in music. It comes from Latin and simply means "work" or "creation." When you see "opus" or its short form "op." next to a piece of music, it usually has a number after it. This number helps us keep track of a composer's different musical pieces. For example, a composer's very first published work might be called "Opus 1." Their next piece would be "Opus 2," and so on.

Why Are Opus Numbers Useful?

Opus numbers are super helpful for telling different musical pieces apart. Imagine a famous composer like Ludwig van Beethoven. He wrote many piano sonatas. If two of his sonatas are in the same musical key, like A-flat major, how do we know which one we're talking about?

This is where opus numbers come in! Beethoven's first Piano Sonata in A-flat major is known as Opus 26 (or Op. 26). This tells us it was an earlier work in his career. Years later, he wrote another piano sonata, also in A-flat major, but this one is Opus 110 (Op. 110). The opus number makes it easy to identify each unique piece.

When Were Opus Numbers Used?

You might think that opus numbers always show the exact order a composer wrote their music. But that's not always true! For a long time, until about the end of the 18th century, opus numbers were only given to pieces of music that were actually published. So, a composer might have written many pieces, but only the ones that were printed and sold got an opus number.

What About Catalogue Numbers?

Some famous composers don't have opus numbers for their music. For example, Wolfgang Amadeus Mozart wrote hundreds of pieces. These included long operas and tiny piano tunes he might have quickly composed.

To help organize all of Mozart's works, a man named Ludwig Ritter von Köchel made a complete list. He gave every single piece a special "K number" (K for Köchel). His list goes all the way up to K622! This system is very useful. For instance, it helps us tell the difference between Mozart's Symphony in G minor K183 and his Symphony in G minor K550.

Other Meanings of "Opus"

The word "opus" can also simply mean a "work" created by an artist. For example, you might hear someone say, "This opus was composed by Chopin," or "This opus is Beethoven's last piano sonata."

When someone talks about an artist's "magnum opus", they are referring to their "greatest" or most important work.

The plural of "opus" in English is "opuses." This is because the original Latin plural is "opera", which could be confusing since "opera" is already a type of musical performance!

See also

In Spanish: Opus (música) para niños