I don't think so, it really is just registered or published. There are cases where the copyright notice matters, but they are handled with care in this listing.
On this page, in section 4, "The myth of the pre-1923 public domain", there is an explanation about authorized publication:
"For publication to have occurred, the work must be issued with the authorization of the copyright owner. A “pirated” copy of a work published in 1922 without the copyright owner’s authorization is, for the purpose of copyright, considered to be unpublished. If a copyright owner subsequently authorized publication in, say, 1970, the work received a 95- year term starting on that date. Reproducing or otherwise using the 1922 work in a way that implicates one of the rights of copyright would infringe on the copyrights established by authorized publication in 1970."
It goes on to specifically reference Happy Birthday to You as an example of this principle.
http://www.infotoday.com/searcher/sep12/Hirtle--When-Is-1923...
On this page, in section 4, "The myth of the pre-1923 public domain", there is an explanation about authorized publication:
"For publication to have occurred, the work must be issued with the authorization of the copyright owner. A “pirated” copy of a work published in 1922 without the copyright owner’s authorization is, for the purpose of copyright, considered to be unpublished. If a copyright owner subsequently authorized publication in, say, 1970, the work received a 95- year term starting on that date. Reproducing or otherwise using the 1922 work in a way that implicates one of the rights of copyright would infringe on the copyrights established by authorized publication in 1970."
It goes on to specifically reference Happy Birthday to You as an example of this principle.