I took some time yesterday night to take a look to improvisor code and estimate the cost of adding musicXML export. Import is indeed more complicated. I downloaded the code of improvisor 3.39. It's the last and only code available. Improvisor inner model is a little bit different than musicXML one. Common practice in musicXML is to don't "time" the chords and put them in the middle of notes. At least, this is my experience with finale musicXML export features. I managed to make a quick and dirty prototype to export a simple melody (no tuplet) and chord root and bass (no extension yet). Chords are in between notes but lily+musicML2ly shoud be able to deal with it. Unfortunately, 3.39 is an old version, and according to Bob Keller the code base changed a lot but it's not public yet. With some more voices, perhaps we can convince Bob Keller and his team to open up the repository to the public. After all, improvisor is a fine piece of software which can benefit from open development, moreover if time and resources are an issue. Lasconic