WARNING: the site is in Korean. Also, it seems as if most of the scores require high composing levels so I guess it's not too great for beginners in music.
http://codehouse.co.kr/code/3450
If you click the first link underneath "Code Music" in the top bar you will be lead to where you can find copy-able music score.
[INDENT]-The composing rank you would need to make that scroll is listed at the far right column. [/INDENT]
[INDENT]-At the title of each song there is a blue bracket with a number and the word ì¸ in it. That indicates the amount of people the song is intended for[/INDENT]
The second link underneath "Code Music" will be where you can listen to songs that don't have scores available to the public yet (works in progress?)
Once you find a song you're interested in...
Copy and paste the entire code starting from MML@ all the way down to the semicolon. When you want to make your scroll, just click on the "copy from clipboard" button in-game
Sometimes there will be more than one code, and that's because some of those songs are for jam sessions. The line above the code indicates what instrument the sheet music is intended for.
I've looked at the music selection just a little bit, and it seems like there's a pretty good selection. Also, there seems to be more party music than one person scores. Happy composing and music playing! I hope this is helpful for some of you. If you have any more questions or need me to find a specific song for you, I'll try to help.