Ted Walther  wrote:

quoted text
> There were no files.  I made up my own music file format.  I took some

> hundred year old sheet music, and based on how I interpet it, I composed

> my particular music files.  From my music files, I automatically

> generate PDF sheet music, midi, ogg, and mp3.  The PDF sheet music is

> not identical to the original sheet music.

Printed sheet music of public domain content is indeed copyrightable.

The copyright does not apply to the content, but to the presentation.

This makes sense, because (at least with classical music) a lot of

effort goes into transcribing, researching the original manuscripts,

adding performance hints and typesetting [1].
I think that the above is also valid if you transcribe from old

sheet music instead of the original manuscripts, so I'd say that

you could copyright the PDF.
Since the midi, ogg and mp3 files reflect the pure content without

any human interpretation, I doubt that they are copyrightable.
I would publish the PDF with a preface, citing the original sources

and outlining the changes that were made. This is common practice.
If you then choose the standard copyright, people will still be

able to make their own compilations from your work.
If you want to encourage direct reuse, why not put the PDF into

the public domain and ask people to credit you if they make

modifications?
I wouldn't use any of the documentation licenses. Those licenses

are for works where you are the original creator, not for transcriptions.
Stefan Krah
[1] Unfortunately, the art of typesetting is on a steady decline, but that

is another topic.