DYNAMICS
"The main job of the recording engineer is to capture as much musical dynamics as possible. The mixing engineer should utilize those dynamics to enhance the expression of the song."
Dynamics in music refers to the interplay and “give and take” between different instruments based on their changes in volume. Dynamics means change, which can occur on many different levels. Even a single instrument can have dynamics that change over time.
There is quite a bit of expression in volume dynamics. When someone SPEAKS LOUDLY it impacts you one way…………. (but if someone speaks softly, you find yourself listening harder and perhaps even leaning in to hear better…) and this greatly changes how you will “listen” what you are hearing.
Dynamics not only applies to volume but also to any other kind of change or movement such as tonal change, intensity (how hard one plays), rhythmic feel, etc. Individual instrument sounds can have different dynamics at different frequencies.
Some home stereos have built in frequency analyzers that show you the entire frequency range. The reason they are always bouncing up and down is that as time is passing different parts of the sound are getting louder and softer.
Dynamics can be felt in single instruments (as it gets louder or softer, or changes tone), relationships between instruments (blending, overtaking, etc) or even the combined sound of a finished mix.
Although these days everyone seems to want their music as loud as possible with no break, music often has important dynamics between instruments that help to convey the emotions of the song that can be lost when mixes are squashed and pumped for the sake of volume.