What is the best way to learn if a song is still under copyright restrictions?

Question

We want to have a public performance of old Christmas songs, with them recorded and post on YouTube, but we don't want to violate copyright laws, again. Recently we learned the hard way that the Happy Birthday song is still under copyright restrictions and will be until the year 2030. So, how do you learn if some old song is still protected?

Answer 1

use something like limewire and don't show your sources.

Answer 2

Most any Hymnal published by a major religeous synod will have a complete history of the composers and possible copyrights for each song included.