MIDI Maestro's most commonly used performance and editing functions may be "mapped" to your MIDI keyboard. That is, instead of fumbling around with a computer keyboard and mouse during a performance, you may instead use your MIDI keyboard to control MIDI Maestro.  The "Setup/External Control" command will open a window similar to this one:

"Actions" are "triggered" when the corresponding key, controller (e.g., pedal), or key and controller combination is pressed on a MIDI keyboard.  Many actions have an "auto-repeat" behavior, and will continue until you release the key and/or controller.

How do I add to or edit this list?

Use the "Add" button to add a new entry, or click on an entry and then the "Edit" button to change an existing entry.  The following window opens:

You may set the input device (physical port and channel) and trigger (key and/or controller) manually by using the controls, or you may allow MIDI Maestro to set them automatically by simply pressing the desired key and/or controller (e.g., pedal) on your keyboard.  When you press a key or controller on your keyboard, MIDI Maestro will automatically update the controls in the window.

First, I play in a rock band and was looking for a nice Midi
sequencer that can be use to play live jam/gig and also have FULL
control over the midi. Having a Start button, with TAP for tempo, and
also playing the introduction until I decide to start the song was a
most. Other sequencer I found did'nt give you the control like
MidiMaestro does.--Steve Hollingsworth