This includes the abcjs system on your WordPress site. To produce sheet music, put a valid ABC Notation string between the shortcodes [abcjs] and [/abcjs] on your page or post.
This also generates MIDI by using the shortcode [abcjs-midi] and can produce both visual and audio music that is coordinated with [abcjs-audio].
Thanks
Special thanks to http://www.beliefmedia.com/ for the idea to load the ABC string from a file, and for the idea to conditionally load the javascript only if there is a shortcode on the page.