Hey there John, I believe that the LilyPond engine is now included automatically in the TexShop distribution, so the Italian university link is moot (it’s where you used to have to download the engine from.) Here’s what I did, quoted from a discussion on this list this past summer:
"Inside the TeXShop Package (Contents>Resources>TeXShop>Engines) there is an “Inactive” directory. If you look inside there, you’ll see a LilyPondEngines-2.1.0b directory, with LilyPond.engine and LilyPond-Book.engine inside. Move those from the Inactive directory up to the Engines directory, restart TeXShop, and you’ll have LilyPond and LilyPond-Book alongside all of your other engines in TeXShop (LaTeX, XeTeX, BibTeX, etc.) Also inside that LilyPond engines directory is a README.txt file, which actually has instructions on how to enable point-and-click!” The full discussion from August is available here: http://lilypond.1069038.n5.nabble.com/Lilypond-PDF-links-in-TexShop-Mac-OS-td235122.html <http://lilypond.1069038.n5.nabble.com/Lilypond-PDF-links-in-TexShop-Mac-OS-td235122.html> Take care, Mike Seifert Quaker Hill, CT, USA