General reply to Messrs Rogers, Peekay and Kastrup!
In the end I googled lilypond and found the \char approach myself.
Right now, I'm settling for it, because as DK hints, both TextPad and
jEdit will save UTF-8 just fine, but the next time you open the file,
you see mysterious blobs, not the intended character. That's why I
committed "mangling" on my previous project!
But I intend to re-visit some German songs I lily'ed a few years ago,
and obviously \char won't really hack it - I like the suggestion of
Emacs, and will go looking for it.