Joe Hutter asked about copyright protection periods.

First, the usual disclaimer...I am not an attorney, etc., etc.

However, there was an enlightening article in the MBSI Journal of
Mechanical Music by Matthew Caulfield in Summer, 1992.  It is worth
reading for details.

The basics are that only melodies predating 1922 can safely be assumed to
be in the public domain.  The 1976 Copyright Act went into effect on
1/1/78 and changed things quite a bit. Up until that time there was a 56
year limit on copyright and renewal; the new law has a considerably
longer period.  Overall, great caution is necessary on items that might
be copyrighted.

If you can, find that Summer, 1992 issue of the Journal of Mechanical Music.
It will get you started on the right track.  Hope this helps.

Bob Ebert