Download 3ml and run it from its folder. You'll need to unzip it XD
Now, google you up a midi file of your choice.
Black Celebration midi
Import it into 3 ml by clcking File > Import Midi
Now narrow it to the three most importnat tracks!
Track> Remove on the ones you dislike
Most tracks ones are tempo tracks-- make sure the tempo is imported.
When you're done, File > Export MML on Clipboard
Pick thread style to psot here
or to bring into game,
When in game, click read from clipboard-- DONE.
You should be able to get the hang of the language by watching a few files
and what happens with the code and be able to work it in more professional
ways with trial and error.
More detailed guides exist elsewhere...