Abrupt Modulation—With a Reason

One classic fault line between “older” opera and the modern school is modulation—how often, and how suddenly, the music changes key. Mozart, Cimarosa, Spontini and their peers tended to modulate sparingly, and when they moved away from the home key, they did it in a clear, formal way.

In the later style—associated with Wagner, Mascagni, and even the older Verdi—abrupt shifts became common. Wagner argued that a composer shouldn’t be boxed into a neat chain of keys but should be free to “swim in a sea of tone.” The problem is that not everyone can swim where Wagner can; many who tried, critics said, simply floundered and sank.

Even in Gretry’s day, people argued about the pros and cons of these sudden key jumps. One musician asked him why he didn’t use them more. Gretry replied that he would—when he had a reason.

“What kind of reason?” the musician pressed.

Gretry painted a scene: imagine a lovestruck young man ignoring a father’s strict commands and flirting with a girl. If the father crept up behind them and astonished the lover with a hearty kick, Gretry promised, he would modulate very abruptly indeed.

In other words: a sudden “change of base” deserves a sudden change of key.