Trouble is, can Monsieurs Guillion be persuaded to make the working parts of Harmony Assistant public domain to be bundled with the DT?
The alternative would be the possibly heretical concept of making the DT itself shareware (with any monies going to pay the licence for any play/display software, and to fund future updates). It's such a fantastic resource that it has to be worth ten dollars of anyone's money - and, of course, the online version is still freely searchable.