The 'correct' version for system 10.5.8 on a PPC chip is, I believe, 2.12.2. Here's the instructions on Ivo Bouwmans' page:
I have a G4.
It says the correct version to download is 2.12.2.
This is the version I used. See my notes where I said :
Using LilyPond 2.12.2.
I quit all applications and used Console.
Here is the message I get in Console once LilyPond opens to the "Welcome to LilyPond" screen and has only the single "LilyPond" menu item in the graphic I sent.
Dec 17 09:00:02 rdlpowerbook LilyPond[203]: +[NSATSGlyphGenerator initialize] invocation. The class is deprecated.
As I said previously, I now have to 'force-quit' to get out of LilyPond.
I got the "bad CPU type" message using 2.13.9. That's probably why the Bouwmans page says to download 2.12.2, which I did. Interestingly, as I noted, 2.13.9 opens further than 2.12.2, though neither of them work under my system 10.5.8.
So given that the GUI doesn't work for me on 10.5.8, I've just gone to using 10.4.11 on my external and that works fine. I'm doing the above steps to try and help the developers. UNFORTUNATELY I do not know enough about Unix to be able to run the complex command-line programs and do LilyPond without the GUI. So I guess for the time being I'm out of luck on 10.5.8, but since 10.4.11 works I'll stick with it.
Thanks again.
RDL