Apple Logic Pro 9 - Manual (Page 656)

Understanding Note Velocities
Each note event features a horizontal line that runs through the rectangle. The length of
the line—in relation to the total length of the note—corresponds to the velocity value
of the note (up to the maximum value of 127). Velocity denotes how hard the MIDI
keyboard was struck when the note was recorded. This also usually indicates how loud
the note is, within the range of 127 possible values, with 127 being the “loudest.”
The Piano Roll Editor also indicates note velocities with different colors.
High velocity Low velocity
This makes it very easy to see the overall range of (and individual note) velocities in a
MIDI region. As you change the velocity of MIDI notes, the color of selected notes changes
in real time.
For further details about color assignments in the Piano Roll Editor, see Changing Note
Color in the Piano Roll Editor .
Displaying Multiple MIDI Regions in the Piano Roll Editor
The Piano Roll Editor’s Link button can be used to simultaneously display the contents
of all MIDI regions in a folder, all regions in a project, or several selected MIDI regions.
You can freely select note events that belong to different MIDI regions, and process,
move, or resize them as required. A help tag indicates the number of selected events and
parent MIDI regions. For example, 8/2 means that eight notes are selected from two MIDI
regions.
When the Link Button Is Turned On
• Each time you select another region in the composition area, the Piano Roll Editor
updates to reflect the contents of this region.
• Selecting several regions simultaneously updates the Piano Roll Editor to display the
contents of all selected regions.
The start point of each MIDI region is indicated by a vertical line of the same color as the
MIDI region itself.
Double-click a note event to revert to a display of the contents of a single parent MIDI
region (the region that contains the note).
656 Chapter 23 Editing MIDI Events in the Piano Roll Editor