Like a stage play or a movie, an opera starts with words — thousands of words. An opera's words are called its libretto, whereas, in a stage play, the words are called the script, and in a movie they're called the screenplay.
Libretto means "little book" in Italian, and that's precisely what it is; your average libretto is scarcely thicker than a TV Guide. But because singing a sentence takes about three times longer than saying it, a "little book," when set to music, becomes a full evening in the theater.
In pop music, the writer of the lyrics is often forgotten. (Quick, who wrote the words to "Somewhere Over the Rainbow"?) In fact, we often don't even know the composer's name — but we sure do remember Judy Garland as the singer!
In opera, the librettist (the libretto writer) likewise gets ignored far too often; we still say "Mozart wrote The Magic Flute," when actually he wrote only the music. Granted, Mozart could probably set the IRS Tax Form 1040EZ to music and create a masterpiece, but he's the exception. Opera composers usually need something more substantial to kindle their imagination, and providing that kindling is the librettist's responsibility.
The plots of most librettos — like most movies and plays — feature larger-than-life characters and situations. Everyone loves a good, juicy story, regardless of its plausibility (see The Matrix or Spiderman, for example). It's fun (or cathartic, or moving) to empathize with the nightmarish plight of an operatic protagonist for an evening.
An opera's libretto has a huge impact on its music. The words influence the rhythm and melody of a musical phrase; the emotion in the drama affects the mood of the music; and the plot determines the overall structure of the opera.
Where librettos come from
Say that you're an opera composer looking for a libretto. Where will you find one? Well, you might see a play and think, "Holy smokes, I could do something with that!" You might get approached by a librettist who says, "I think that we could make music together." Or if you're very lucky, you might even receive a commission from a patron who has a librettist in mind and money to burn.
But regardless of how you and the librettist discover one another, your relationship is a collaboration, often a very intimate one. Like a marriage, this relationship could be tempestuous — after all, we're talking about gigantic colliding egos here!
Opera's most famous librettists
Opera history includes three truly legendary librettists: Lorenzo da Ponte (who collaborated with Mozart), Arrigo Boito (who wrote two scripts for Verdi), and Hugo von Hofmannsthal (Richard Strauss's greatest collaborator).
Of these three, the most interestingwas Lorenzo da Ponte (1749–1838), partly because he provided Mozart with the inspiration for Don Giovanni, The Marriage of Figaro, and Così fan tutte, and partly because of his colorful life. It's a long story, but suffice it to say that da Ponte was a Venetian priest who fathered a child with a married woman, was run out of town, moved to Vienna, forged a letter of introduction, passed himself off as a librettist, worked with Mozart, had several affairs with leading divas, moved to London, got heavily into debt, and fled to New York, where he started a grocery store and the Italian department at Columbia University. It's safe to say that Lorenzo da Ponte is the greatest librettist ever to be buried in Queens.
Arrigo Boito (1842–1918) was a composer in his own right (he had used his own libretto for his opera Mefistofele). But his collaboration with Giuseppe Verdi, who was at the height of his powers and the end of his brilliant career, produced two of the finest Italian operas ever: Otello and Falstaff.
But when it comes to emotionally fraught, therapy-ready relationships, it would be hard to beat that of Richard Strauss and his librettist Hugo von Hofmannsthal. Though they worked together for 23 years, and often lived just an hour apart, they rarely met. Through nearly three decades of correspondence, Strauss and Hofmannsthal never called each other by their first names.
Both men were brilliant but touchy; time and again, one or the other would threaten to pull out of the project, and the other would have to bully or mollify in response. For all their bickering, their collaboration gave birth to some incredible operas — including Elektra, Der Rosenkavalier, and Ariadne auf Naxos.