|"Wachut Auf" by Bach. At least|
that's what we call it.
Well, yes you are. In parts one and two I explained the basics behind the naming of instrumental works. Since they usually just have a generic name, some type of numbering is necessary to tell them apart.
But what about vocal music? After all, songs in popular music all have unique titles. That's true. And those titles usually come from one of two places: either a key word or phrase from the chorus of the song, or an evocative title assigned by the composer(s).
Begin at the beginning, so none may sleep
Classical music works a little differently. Like instrumental music, most vocal and choral works originally didn't have assigned titles. So the practice evolved of referring to them by the first line or phrase of the text.
That's why Puccini's popular aria from "Turandot" is called Nessun Dorma. The phrase ("None May Sleep") is a repeat of the decree Princess Turandot has issued, that none may sleep until the name of the Prince has been discovered. The Prince echoes the call, which then leads into his aria of love. But since the first words he sings are "Nessun dorma," that's what the aria's called.
The same holds true with arias from oratorios and cantatas. "Are We Like Sheep" is a famous chorus from Handel's "Messiah." Ditto the "Hallelujah" Chorus -- so called because that's the first word sung.
And the pattern holds for unnamed larger vocal and choral works as well. Bach's cantatas all take their titles from the first line of text. "Wachet Auf" is the first line of his Cantata No. 140. Want to sing the second aria from that work? Then you're talking about Mein Freund ist mein!.
A Sense of Entitlement
Works can have titles assigned, of course. Most operas take their titles from the lead character, or the plot. And if a poem is set to music, the title of the poem usually becomes the title of the musical work as well. Schubert's lieder mostly follow this pattern, as do Schumann's.
Missa No Understand, Obi-Wan
Reciting titles for medieval and renaissance masses can make one sound like Jar-Jar Binks, but there's a reason for that nomenclature as well. The Roman Catholic worship service is known as a mass, or missa in Latin.
From about 1100 to 1600, it was very important to have liturgical music tied to tradition. So much so that composers usually uses an existing Gregorian chant as the basis for their composition. As time went on, other types of music were incorporated, including some secular (and in some cases pretty dirty) songs.
Titles for these masses always referred to the root melody the composition was based on. So the Missa L'Homme Armee is a mass based on the popular song "The Armed Man." Actually, several renaissance composers have a Missa L'Homme Armee in their catalog.
It's like the French have a different word for everything! - Steve Martin
The important thing to remember is that classical music has been composed for over a millenia in virtually every country in Europe, as well as most of the Americas, (and a few other places besides). Titles almost always come from the language of the text. So that's why you have German, Italian, French, and even Latin titles for works.
So the titles of these works isn't meant to obscure, but to provide additional clarity. You might not know what Christ Lag in Todesbanden (Bach's Cantata No. 4) means, but you at least you know it's a German work.
There are many other ways classical works are named. If any are puzzling you, just leave me a note in the comments field. I'll be happy to research your question and supply an answer. Classical names shouldn't be a barrier to the enjoyment of the music. It doesn't really matter what a work is called, just how it calls to you.
The Naming Game, Part 1, Opus 1!
The Naming Game, Part 2: Cataloging Chaos