Hello,
I've begun to use PMD98 for making music (thank you Noyemi for the good tutorial). It looks very interesting, yet I'm not very found of the MML (MMHell) syntax. In fact I'm used to the ABC notation syntax which is just easier and looks more logical. For example:

In ABC :
X: 1
M: 4/4
L: 1/8 % you can define the base note here
Q:1/4=120
K:C % 0 sharps
C2 D2 E2 F2| G2 A2 B2 c2| d2 e2 f4| g2 ab c'4|]
In MML:
t120 cdefgab>cdef2ga8b8>c2
Here are a few remarks:
- In ABC we add bars to separate mesures. It might look more readable (maybe it 's possible to do the same in MML).
- In abc, we have at least 4 visual octave ranges: C, C c and c' (C, being the lower). It's possible to add marks to get even lower, for example C,, or higher (c'')
It's also easier, in my opinion, to read (and write) music this way. Just by a quick glance, we can see if a part is lower than the other. After a few < > < < > in MML, it's more tedious.
- In ABC, we use the opposite for length of notes. If 1 is the base, 2 means it doubles the base length.
It may just be an habit, but the advantage is you can count to check if your mesure or part is complete or not:
d2 + e2 + f4 = 8
g2 + a + b + c'4 = 8
I wish someone make source based music processor using the ABC langage one day :=)
Btw 3ML is awesome to convert from midi to MML: http://3ml.jp/download.html