Somebody named ELLE, a long time ago, made a composer program for Mabinogi. The program would allow you to look at your notes and see what you could correct like looking at a real score. It can also compress your MMLs and squeeze your characters to be as small as possible in order to get lower ranks to play them and more compatible performances. However, the program is written in Japanese. Luckily, ELLE translated a few things to English.
Before you get started, you should set up your sound card to play Mabinogi's raw MIDI instruments rather than your original Synthesizer. Here's how you do it:
How to set up your sound card to load Mabinogi's MIDI Channel:
Go to "Settings(S)", or press "Alt + S."
Click on "MIDI Config(M)", or press "M."
Under "MIDI Output(O)" option, choose the "Microsoft DirectMusic DLS ?音?." (Should you have more than one version, any one will do.)
Under "Microsoft Music DLS 音色設定(I)" field, type in / copy & paste / click on "..." and browse your MSXspirit.dls file (usually under ...\Mabinogi\mp3\MSXspirit.dls), then click "Open."
How to export your score on a clipboard:
When you're done completing a song, you can put your score on a clipboard for you to paste into the game or on a forum for everyone else to try.
Click on "File(F)" and then click on "Export MML on Clipboard(E)."
You can also press "F7" on your keyboard or click on the button.
On the right, you'll see a list of tracks. Check and uncheck them until you've decided on which 3 tracks you want to export, should you have more than 3 tracks to edit on an MML file.
On the left, in the "Format(F)" field, you'll see how you want to export your score:
Mabinogi style will export your score so you can load it up in-game by clicking on the "Read from Clipboard" button.
Thread Style will export your score in a forum-fashioned manner, so when you paste it, the tracks will be sorted properly, and you can give extra information about the song you composed (this can be edited in the "Property(R)" window in the "File(F)" menu).
MabiMML Style will take ALL of your tracks and MML information on the clipboard if you ever save your MML files using a text editor like Notepad.
Optionally, in the "Optimize(O)" field, you can check the "Optimize and Export(E)" option to optimize your selected tracks' codes and abridge the length.
This is highly recommended to avoid going over your Composition Rank's limits.
If you exported using Mabinogi or Thread Style format, a window will pop-up saying what rank is compatible with this score, and will sort out which fields (Melody and Chords) your tracks will be in.
If you told the program to optimize your score, the pop-up will also tell you how many characters in each track there are before and after optimizing them.
How to import your score from your clipboard to 3MLE:
If you have a score on your clipboard from anywhere, you can paste it into the program.
Click on "File(F)" and then click on "Import MML from Clipboard(I)"
You can also press "Shift+Ctrl+V" on your keyboard or click the button.
Set your options, and then click on "OK."
The "Info(I)" field will tell what type of score you have on your clipboard.
The "Reading System(F)" will give you an option on whether you want to add the tracks to your current project (Add Read(A)), or start a new project with them (New Read(N)).
The "Set Instrument(S)" will allow you to pick what instrument you want all your tracks to play with. (You can set these later in the upper left corner of the track chart tab.)
If also helps peopel who can't read sheet music but want to convert songs because you can import midis and just check the notes it makes.I don't think it converts automatically though.
I'm wrong, it does actualyl convert the songs into MML for you at the bottom.
It is much more complicated, though. There are some tracks that have more than one chord which can't be imported unless if you check that one and only track, and then check "MIDI Track -> Multiple MML Track(S)."
For example, I imported an arpeggio track without checking the Multi option, and all I'll hear is long notes rather than a marathon of short notes added to it.