[VOA]

I thought after 25 years, a song becomes part of the “public domain”.

I'm no lawyer, but I think copyrights are much longer now.
This general trend to extending the copyright "lifetime"
got rolling when Charles Dickens got p-ssed over American publishers
printing/selling copies of his works...with no $$$ going to Dickens.

I don't know if it works under a different system but IIRC
somehow the film studio that did "It's A Wonderful Life" somehow
let their rights to the film lapse...that's why it got revived
by Christmas-time showings on many stations.
But I believe the film studio (or it's successor organization)
was able to re-establish rights.
And that's why you only see it on NBC these days.

I welcome more informed posters to correct any goofs I've made
on this topic.

[supercat]

But I believe the film studio (or it's successor organization) was able to re-establish rights.

IIRC, the copyright on the film itself lapsed since the creators failed to renew it. The copyright on some of the music within the film was renewed, however, and did not lapse. The film producers probably got an agreement with the copyright holders of the music not to license it to anyone else who wanted to use it with the film.

By my understanding, if someone wanted to release a version of "It's a Wonderful Life" with all the copyrighted music replaced by something else, one could legally do so. Such a person would be so thoroughly slammed for altering a classic, though, that I don't think one would likely bother.