Licensing question: content deemed to have entered the public domain?

["David H. Gutteridge" <david%gutteridge.ca@localhost>]

Hi all,

I've packaged music21, which is a Python project for computer-aided
musicological analysis. It's defined as BSD or GPL (so far, so good).
Its full distribution also contains a good deal of notated music,
which they've deemed to be in the public domain. When a work enters the
"public domain" is defined differently depending on the jurisdiction.
Does TNF/pkgsrc have a set definition of the applicability of when a
copyright term has elapsed? (E.g., perhaps we'd use the US definition,
since TNF is a US foundation? music21 is an MIT project, so it would
use the US definition. Though, TNF has international mirrors.)

While this might seem a bit esoteric for a project normally concerned
with software code, part of why I ask is because oftentimes copies of
distribution archives get uploaded to TNF servers. Were this to happen
here, TNF could hypothetically be redistributing sheet music that may
be in the public domain in, say, the US (copyright expiry 70 years
after author's death), but not in, say, Mexico (expiry 100 years after
author's death), and some music publishers and composers' heirs have
been litigious with sites like IMSLP.

If it's a concern, the music21 project also offers a "corpus-free"
distribution that removes all these scores. But I'd prefer to keep them
in. (From what I've determined, all the presently included works are in
the public domain in any jurisdiction. But the selection may change, of
course.)

To re-frame this question, this is about handling licensing for what's
effectively "data" rather than code. Where projects diverge in terms of
this -- code under one set of terms, specific "sample" data under
another -- what is the general pkgsrc practice for handling this? Or is
that normally a concern at all?

Thanks,

Dave