To play a range of midi messages, use the tag 1 and tag 2 buttons.   This will define the range,  Then click on the play button.

To cancel the range click on the cancel 12 button.

This happens in two stages, first tag 1 then tag 2 are canceled.

If active (the color of the button is green), clicking on any of these two buttons, tag 1 or tag 2, positions the corresponding midi message in the center of the midi message window.