Apple Logic Express 9 - Manual (Page 731)

Velocity Limiter
Limits the velocity to a maximum value. This is perfect for transforming instrument parts
that are too strident, by limiting the velocity.
Change the Max operation field value to limit the velocity to a maximum value. This is
instantly reflected in the map area below.
Fixed Note Length
Creates constant note lengths. Useful on many instruments, particularly drums and other
rhythmic parts, such as pianos, clavinets, and basses.
Change the Length value field in the Operations area to change the lengths of all selected
events to the chosen length. Both shorter and longer events are changed to match the
length value you have defined.
731 Chapter 26 Editing MIDI Events in the Transform Window