It is interesting what simply changing the tempo of a piece can do to affect the mood of a composition. The effect can be more striking than is readily apparent. This can be seen in only slight changes that can vary from conductor to conductor in a symphony setting. For example, take Prokofiev’s “Dance of the Knights” from Romeo and Juliet, Op. 64. Compare and contrast the following two versions of the same piece. The first is Valery Gergiev conducting the London Symphony Orchestra.
The second is Mark Ermler conducting The Orchestra of the Royal Opera House, Covent.
Ermler’s lead is just ever so slightly slower than Gergiev’s lead, but do you hear the difference in mood? Gergiev’s LSO performance is a bit hotter, more rousing while Ermler’s OROH performance is a bit darker but also a bit more melancholy.
Perhaps one of the most recent and striking illustrations of how tempo can change a piece of music is from the cinema. For the film “Inception” by Christopher Nolan, composer Hans Zimmer took an actually mathematical approach to transforming tempo and made something spectacular. In “Inception”, the films protagonist Dom Cobb (Leonardo DiCaprio) is an industrial spy who steals information using a “dream sharing” technology. Run afoul of the law and on the run from U.S. authorities, he sees a way to be reunited with his children when an executive hires him for the very dangerous job of planting an idea in a competitor’s mind. Much of the film’s soundtrack is built on themes created by speeding up or slowing down the tempo of French balladeer Édith Piaf’s “Non, Je Ne Regrette Rien”. It is the song used to “kick” the dreamers from one level of the dream to another. There is a catch though. (Spoiler) Each level of the dream runs at a different rate of time. Zimmer took those differential times to create music that is not only an interesting intellectual puzzle, but very evocative and moody music that complemented the on-screen action. Here is Piaf’s original song:
For contrast and comparison, here is Zimmer’s “Time” from the “Inception” original motion picture soundtrack, played live:
Here is a clever side-by-side comparison put together by YouTuber Cameron Whitehouse:
“What is time” leads to the question “how important is timing”. Time and timing can make all the difference in the world. This is true of music. It is true of everything in our four dimensional universe. But in music in particular you can hear the transformations both radical and subtle that tempo can have on a particular work.