Terraced dynamics is a musical style characterized by abrupt volume shifts from soft to loud and back within a piece, explains Artopium.com. Terraced dynamics ignore the traditional slow volume changes of the crescendo and decrescendo.
Terraced dynamics are most notably used in Renaissance and Baroque classical pieces due to the prevalence of the harpsichord during these periods. The harpsichord is a Medieval musical instrument similar to the piano, often constructed with two keyboards to allow for a greater musical range. Unlike the piano, the harpsichord is not capable of producing subtle variations in volume. This limitation is responsible for the prevalence of terraced dynamics in Renaissance and Baroque music; as crescendos and decrescendos were generally impossible, composers were forced to employ this more abrupt style.
There are, however, some disagreements among scholars about how widely used terraced dynamics were. According to musicologist Robert Donington, Baroque musicians constantly varied volume, without notation, by use of fairly sophisticated methods. For instance, a musician could create subtle volume variations by using more keys at once, as the greater the number of keys used, the louder the chord sounded. Despite these arguments, it is clear that terraced dynamics were used less and less as time passed, suggesting they were the norm in Baroque music. As music progressed, volume notation became more and more complex, suggesting much simpler volume changes were employed in the past.