How to get there
Click the MIDI Tool 
. Select some measures. (If you’re editing a one-staff
region, double-click to enter the MIDI Tool window.)
Specify the MIDI data type you want to edit by choosing Key Velocities
from the MIDI Tool Menu. If you’re in the MIDI Tool window,
select the region you want to affect by dragging through the "graph"
display area or by selecting the handles
of individual notes whose MIDI data you want to edit. Choose Add from
the MIDI Tool Menu.
What it does
The Add dialog box’s contents change to reflect your MIDI data type selection (key velocities). Its function is to add a fixed amount to (or subtract a fixed amount from) the key velocity of every note in the selected region. Because it adds an absolute amount to every selected note, the Add command preserves the relative proportions of the existing values.
For example, you can specify that each note in a selected region should be played back with slightly more volume by adding, for example, 20 MIDI velocity units. (MIDI velocity is measured on a scale from zero, which is silent, to 127, which is very loud.)
See Also:
