The other day while driving, I heard a familiar-sounding piano sonata on WCRB. It was one I’d heard before, in fact one I was familiar with. I could accurately anticipate the music, which was obviously Mozart’s, in some spots. But I couldn’t place the damn thing! When I reached my destination, I stayed in the parking lot and kept the radio on to the end. The announcer said only that it was Mozart’s “Piano Sonata No. 2.” This wasn’t very helpful, since there are different numberings in different editions.
The numbering of musical works is tricky in general. For many composers, there are generally accepted numbers, but Mozart’s sonatas aren’t the only case where there’s confusion. Schubert’s symphonies are usually numbered 1 to 9, even though No. 7 is just a sketch. The “Unfinished” is No.8 and the “Great C major” the 9th in this scheme. Some lists, though, have just eight symphonies. They make the “Unfinished” the seventh and the C major symphony the eighth, or vice versa.
Sometimes there are gaps, usually when a work attributed to a composer and given a number turns out to be by someone else. That’s why, although Mozart’s symphonies are numbered up to 41, there is no Symphony No. 37. There are also some symphonies by him that turned up after the current numbering became canonical, and they don’t have universally accepted numbers. Giving them numbers after 41 would suggest that they were late works, but none of them were. There’s also the question of what counts as a symphony. His “Symphony No. 32” is in one short movement and is more like what we’d call an overture today.
Works in a numbered list weren’t always written in numerical order. When Beethoven’s Fifth and Sixth Symphonies were premiered in a single concert, their numbers were swapped compared to the ones we use today. Schumann wrote his Fourth Symphony before the ones that are now numbered 2 and 3; he revised it heavily and published it after those others. This means that his Third Symphony, not the Fourth, was his last.
Bruckner has a “Symphony No. 0.” He wrote it after his First Symphony but later was dissatisfied and withdrew it, writing “annulliert” (nullified) on the score. It acquired the number zero as a kind of nickname and still gets performed occasionally. He also wrote a symphony that got the number “00,” which doesn’t get as much attention.
If you’re writing about a musical work, its number isn’t always the best way to identify it. Everyone knows what Beethoven’s Fifth Symphony is, but a lot of classical music fans will draw a blank on Haydn’s 94th symphony. If you call it the “Surprise” Symphony, they’ll know which one you mean. Provided they speak English, that is. In German-speaking countries, it’s the “Symphony with the Drum Stroke.” Mentioning the key can help, but composers reuse keys. Years ago, any regular concertgoer would know that “the C minor Symphony” means Beethoven’s 5th, even without mentioning the composer. That’s fallen out of style as a primary identifier. “Beethoven’s F major symphony” could mean either the 6th or the 8th. Haydn wrote over a hundred symphonies and couldn’t avoid repeating keys many times.
The titles which works have often didn’t come from the composers but were added years after their composition by someone else. Some titles are better known than others. Beethoven called his Sonata in C sharp minor, Op. 27, No. 2, “Sonata quasi una fantasia,” but a lot of listeners won’t recognize that title (which it shares with Op. 27, No. 1). A poet named Rellstab stuck it with that name. The first movement arguably suggests a moonlit scene, but if the third movement alludes to anything moonlight-related, it’s a rampaging werewolf.
Catalogue numbers are the most reliable identifiers, but not everyone knows them. The works of nearly all major composers have an opus number or a number from a named catalogue. There are lots of catalogues, to the point that there are catalogues of catalogues. Some of Beethoven’s works have WoO numbers, which stands for “Werke ohne OpusZahl” in German or “Without Opus number” in English. A number for a work without a number sounds like an oxymoron, but that’s how it goes. Opus numbers are usually assigned by the composer or publisher and don’t represent the complete set of works. Beethoven’s WoO works include some well-known pieces, such as “Für Elise,” along with abandoned fragments.
To identify a Mozart sonata, I’d use the Köchel number and the key. For instance, the sonata which I mentioned at the start of this post was the F major sonata, K. 280. Sometimes you have a choice of numbers. The Köchel catalogue has gone through multiple revisions, and some numbers have changed. Schubert’s song “Erlkönig” is known both as Opus 1 and Deutsch 328. The “Opus” numbers of Schubert’s works, some self-assigned and some posthumous, don’t cover all his music. Otto Deutsch’s catalogue, first published in 1951, is now considered the best numbering system for Schubert.
If you have occasion to write about works of classical music, I hope this helps you rather than leaving you feeling more confused than before.