When I made an attempt to classify MIDI files downloaded from the WEB, I found that there are many similar ones. The difficulty was that sometimes they slightly differ from each other: they were not identical, but similar enough.
To make the compare of files easier, I wrote a small
utility which finds common blocks in files. Here it is presented.
It is evident from above picture, that files are similar, but not identical.
You can also use this utility to compare all types of files, for example texts (especially it's interesting to compare .TXT and .BAK files) and pictures.
Try my program if you want - it's free. I'll be happy to receive any comments and description how you use the utility. My E-mail email@example.com