Disklavier

There is that MidiKit program (free) for OSX which is quite good at revealing the midi file content and permits edition. (Same developper of the very good midi player Qmidi (I use only that from my Imac to my MPX-1, great for library and playlists and mixing capabilities , I complete it with the "Midi Patchbay" pgrm which permits as extra to send all channels to a unique chosen one (handy for sending all to channel 1) and some other features, its also free , quite oldish but still works like a charm under Sierra. Lastly there is a very good one "Midi-Connections" which seems not to be available anymore but still works fine and has a lot of midi handling feature (I could send it to you ) it was i think free also.