Hello Mr Magill1
If you are still looking for an .abc file editor/player for Mac OSX, you could try "Ernie" (Version 1.0b8 (1)).
This is the information that is given on the software's "About Ernie" menu item.
About Ernie:
Ernie is an application for viewing sheet music written in the abc notation.
For more information on Ernie, visit http://geophysics.kos.net/ernie/
For more information on abc notation, visit http://abcnotation.com/about
Licencing:
Ernie is free to use and distribute, but may not be sold without the permission of the author.
I have used this, and have to say that the editor is not hard to use, but you do need to be reasonably conversant with the .abc file format.
Hope this helps.
Xtin Basher