This is a long post related primarily to Playlist improvement and bugs.
The "Start from first Note" works perfectly (can you share what you did?).
The Playlist is an improvement but still has many things to work out.
File highlighting in Midi Player playlist is following the mouse movement, it should not do that.
Highlighting a file should be done only by clicking it.
I can't select several files from the playlist to delete them, I have to go one-by-one or hold the delete key.
I also have to be careful not to move the mouse while deleting so that I don't del a different file by mistake.
Clicking a single file then clicking a different file while holding shift should select all the files between them, Ctrl for individual file selection.
1. Basically the playlist should behave like Windows Explorer when set to "Details" view type.
Winamp, AIMP, Foobar, "any music player" etc.. all their playlists behave like windows explorer when selecting (click, shift, ctrl) and deleting files (organizing).
Dragging files from windows explorer to playlist is working properly, you nailed that.
2. It would be nice that that player finishes playing the song even if it was already deleted from the playlist.
With AIMP (winamp), I usually empty the playlist while still listening to the last song, and adding new songs to a clean playlist.
If the playlist is empty, the song will finish playing and stop the player.
If files are added, the player will finish the playing song and start playing from the new first song.
Currently, the player stops and sends a reset command when I select "Remove All".
It also starts playing automatically when adding songs to an empty playlist, it should not do that, the proper behavior is explained above in #2.
"Auto play (next song)" and "Start playing when adding files to empty playlist" are two different things.
3. I think that "Repeat Playlist" should be an option (user switchable), and not the default like it currently is.
The default should be to stop the playlist at the last song and the "Repeat Playlist" should be the name of the switchable option, similar to "Repeat One".
4. Multimedia Key (on my keyboard) "Stop" is not working yet since you implemented a stop button in the player.
Play and Next/Previous are working.
The above are standard behavior of playlists across many players, Foobar 2000, AIMP, ITunes, etc...
Do you keep a "Fixed, Added" list to show when v3.5 released?
It'll be huge! v3.5 is already miles ahead of v3.4.2 in terms of functionality. 😀
I hope these are not hard to fix/implement and I'm not making your life harder that it should.
PS.
I have a SC-55 MKII (hardware) on the way.
Real midi interfaces, slow hardware buffers, real cables, all will reveal more because they are not ideal like a software midi loop and a VST plug-in.
Looking forward to this.