outland144k
Beagle, it's 70 years after the death of the author, not 70 years after the song was written. While he wrote the song in 1929, Albert Brumley died in 1977, hence the copyright is still active.
The one case I'm familiar with conflicts with the notion that it's based upon the death of the author. All of Pucinni's operas except the last one are now in public domain. This was as of maybe eight years ago, so perhaps they now all are. This is in the US, by the way. But if a late work is not PD and earlier works are, then that would strongly suggest the author's death is not the sole determining factor.
Edit: It just occurred to me that the final opera was never completed by Pucinni. A student of his (or something like that) finished the final few of minutes. That might explain why that one opera still held copyright. The guy who finished, who counts as one of the composers, probably died quite a bit later.