What is the difference between dynamics and
volume change?
Dynamics like "fff" or "ppp" indicate the note velocity.
By principle, they can only be applied at the time the note is
started. For example, a pianist can press a key more or less
strongly, but cannot control the sound once started.
A different velocity (starting power) produces a different sound, and not only a change in
volume.
A piano played fff is not simply a piano ppp played louder.
However, some instruments can produce volume variations while note
is played. For example, a violinist playing a long note, or a
flutist who can reduce the breath pressure to soften the
volume.
When switching to graphical edit of note
velocities, sometimes the line splits into yellow and red.
Why?
The red line shows the actual (played) velocity, while the
yellow line shows the written velocity. These two curves are
different as soon as a dynamics is present in the score.
