If you want to learn by ear, which to tell the truth is a lot easier, you can play the tunes and follow them but I wish the tunes could be looped so they play as long as you want them too. Is that possible?

That's usually a control in your player program. I use the old QuickTime Player program on this machine (MacOS 9) and it has a "Loop" option in one of the main menus. It should be available somewhere no matter what player program you're using.

I would suggest midi and small graphic files (gif or jpeg) - there's no point in using mp3 for computer-generated tune files, it's not like there are interpretive subtleties you might miss. And the graphic scores are accessible to people to don't have Noteworthy or aren't using Windows.