I've added support for compressed MusicXML .mxl files to my ABC Transcription Tools.
Here's an example of importing an .mxl file of the J.S. Bach Two-Part Invention #1 into the tool, converting it from MusicXML to ABC, displaying and playing it with a harpsichord sound.
Sound recorded using only the microphone in my monitor, no post processing of the audio.
Try my free ABC Transcription Tools:
http://michaeleskin.com/abc
User Guide:
http://michaeleskin.com/userguide.html