What MV version are you using ?
Tried with Producer 7.4RC, never worked : when I right click it open a contextual menu.
The preview player is available in View/Preview menu but I can't load anything into it.
I'm a bit lost on this because I don't understand how you can listen to a track without loading it into a deck.
Most of the actual MIDI commands are in this thread :
viewtopic.php?f=268&t=15072&st=0&sk=t&sd=a&hilit=MIDI+command