Quick lesson for non-musicians: the word “opus” (often abbreviated to op.) means “work”. Composers catalog their works by opus number, which generally go in chronological order.

Many composers had their musical beginnings early in childhood, writing pieces for themselves to play, experimenting with music on paper. With the exception of Mozart, these compositions are usually just childhood games, and at best might amuse music aficionados who are curious about a composers’ early thoughts. When a composer grows up and begins to pursue “adult” composition, they begin to assign opus numbers. Opus One is probably not the first piece s/he ever wrote, but it represents the first piece that s/he releases to the world as representation of his/her contribution to Art Music.

If you are older than 25, you might think back to those early years of adulthood. A young composer’s early music reflects many of the same conflicts that many of us went through at this time. An opus one might be very conservative, trying to please one’s elders. It might be extremely edgy, trying to buck tradition and the establishment. It might be a desperate cry for attention; it might be an attempt to find some peace.

Opus One can also provide an interesting framework once a composer dies – you can listen to how far a person has come, and consider what caused him/her to change. Mention Stravinsky, and most people immediately think of the Rite of Spring, one of his earliest works (and one of his edgiest.) But after that period, Stravinsky wrote a ton of music which in no way resembles those early ballets. He came a long way, but most people know him for his early stuff.

Carl Nielsen is considered the iconic composer of Denmark. His Opus One is fairly conservative compared to his later music – a Suite for Strings.