leenia, I did a Google search on "lament, tristan, midi" and had just 73 hits. Most of them were references to 'Tristan und Isolde,' but a couple were the correct one. A lot easier to delve through than 1830.

Interestingly enough, one of my hits had the same midi Jon referenced above, but it was not from the same site. These things do get around, in fact I have the midi file on my hard disc and I know it was from neither Jon's site or the one I got in my search.

One question - how are you going to determine whether a version has errors? Lamento being one of the more famous Medieval works, it has probably been 'folkified' more than most of the stuff we deal with on this forum. Seems to me it'd be quite hard to lay hands on an 'authentic' version.