Conversion was delivered as ordered.

If Jon is "the" Jon of folkinfo.org, he is a well-respected person in the ABC scene and not likely to recommend things that will be complained about lateron.

The Windows Media Player is notorious for sliding down MIDI output when finished with it. Microsoft declares this the way to do it, so some programmers follow, others don't. abc2midi seems to use its own sound mixer, so the problem does not arise at all.

I use that package for Windows, with ABCexplorer as a user interface (midi2abc replaced by MidiZyx2abc, which also works on its own without command line, producing no sound at all).

It is always a good idea not to be the first one to try out new or obscure software. If it is on the list kept by the inventor of ABC, it is not necessarily excellent, but you are likely to get some support by Jon or other experts.