David
No nearby Lilypond icon.
BOMAArchiverHelper didn't work.
I downloaded again, did the Ctl Shift, this time the Open With
lead to Adobe Reader but Adobe can't open it either.
Any other suggestions?
Start the Terminal
Type the following and make sure to type a space after the letter f:
tar -xjf
Then drag your downloaded Lilypond installer file into the Terminal
window (its name will appear after what you already typed)
and then hit the Return key.
Wait a minute for it to finish, and the Lilypond program should
appear in your home folder (the one with your name on it, that is).
Drag the new green Lilypond icon into Applications.
Hope that works.