MIDI Chase
When chase is enabled, any MIDI notes that are received via the connected MIDI In device are used to select the corresponding trigger when in edit mode.
So for example if your Zendrum is hooked up to your MIDI In port and you physically hit a trigger that is assigned note #36, then any triggers in your project file that also are set to note #36 will be 'selected'.
For crossfade enabled triggers, only the first, or lowest, note is compared to the received note number.