The backing track function has now been added.
Here's a screen shot of the updated GUI.

Many HOT Key functions have been added.
Add New Song CTRL+N
Delete Song CTRL+D
Display Lyrics CTRL+W
Play Backing Track CTRL+P
Stop Backing Tack CTRL+O
Next Song CTRL+>
Previous Song CTRL+<
Show Sheet Music CTRL+M
Show Song List CTRL+S
Jump to Page 1 CTRL+1
Jump to Page 2 CTRL+2
Jump to Page 3 CTRL+3
Jump to Page 4 CTRL+4
Jump to Page 5 CTRL+5
Jump to Page 6 CTRL+6
Jump to Page 7 CTRL+7
Jump to Page 8 CTRL+8
Jump to Page 9 CTRL+9
Jump to Page 10 CTRL+E
Jump to Page 11 CTRL+T
Jump to Page 12 CTRL+Y
Many bug fixes and new features added + enhancements.
The EXE in my first post has been replaced with the current version for anyone interested in testing it. Just remember, it's beta software and not for actual use yet. Almost there.
Regards
James.