Probably should have asked something like this a long time ago. Which MML are you using? Music Macro Language or Music Markup Language? The two are both MML but both very different. The latter is an XML-based standard while the former is apparently used a lot by chiptune authors in Japan.
And now that I look at the video, the MML code doesn't look very XML-like at all, so I'm guessing that the MML you are using is Music Macro Language (according to Wikipedia it is often erroneously called Music Markup Language).