If you want to use the bottom screen, then use the xscreen command. To save, use the save command from inside the program. Xscreen 2 will remove the keyboard and allow for us of the touch screen.
A cheaper, more time consuming way is to look up the notes for a song and make a MML out of it. I suggest looking up impossible remix on you tube. It shows songs on piano. Some people already have public MML text files you can download.
I recommend it if you want to start learning how to code. It helped me a lot when I was learning c++. there aren't the exact same or even close, but if you're interested in coding, then this will help lay some ground work for other langues. Plus, everyone is super helpful when questions are asked, so don't let that be a problem. there a also a ton of free games to download and play.