Dynamics

By Kelvin Sholar

Loudness is a psychological property which corresponds to sound pressure amplitude or intensity. In music theory, loudness is conceived in terms of dynamics; or levels of how loud or how soft music is.

There are two basic ways that we hear changes in loudness of dynamics. First, a performer plays quieter or louder. Second, we add or take away instruments that play at a time in a group performance.

When musicians want to indicate how loud or quiet music should be, we write Italian words. For example, we write “piano” to indicate quiet, or we write “forte” to indicate loud. Such Italian words for loudness are called Italian dynamic markings.

The study of loudness or dynamics in music also includes accents, where a performer emphasizes a tone by playing it louder than others – or vice versa de-emphasizes a tone by playing it quieter than others. Dynamics also include gradual changes in loudness and sudden changes in loudness.

Loudness is subjective; even though we can objectively measure amplitude in decibels, what is loud to one person can be quiet to another. This is why Italian dynamic markings are not absolute and exact. This means that different composers and performers use them in different ways.