Further I'm not 100% sure if ae is really still needed in times of latin modern and cm super. Ralf, are you still on the list? Can you help here?Catching up ... Given Latin Modern, ae is obsolete from my point of view. Actually the above example uses Latin Modern fonts in the end.
I'm sorry I really don't know anything about Texlive fonts. Does this mean that the best solution would be to incite the author of Songwrite to use a more modern font? In this case which one?
Cheers, JM.