An Exercise in Copyright Law

I don't mean to be crude at all when I say that copyright law is an absolute and utter b*tch, but it is. It really is. It's easy enough for my pieces which are before 1923, since all of those copyrights are have entered the public domain. However, for the ones between 1923-1950, I have to make sure that their copyright wasn't renewed in the 28 years after their publication. If it has been, it means there is a 95 year wait period before it enters the public domain. Needless to say, it's not been an easy task.

Take for instance, this lovely song:

I look, and I look, and I cannot find a secondary publication of it which may mean that it wasn't renewed. All copies I am aware of are published in 1929 for the movie, The Pagan. The question, however, remains, does that mean its copyright hasn't been renewed? I'm not entirely sure, seeing as there was a movie made in 1950 (starring the esteemed queen of the waves, Esther Williams) that features the song, and is appropriately called Pagan Love Song. It is all so confusing!

I've also found out that the publisher, Robbins Music Corporation, is owned now by ubiquitous Alfred Publishing Company (or Belwin) which makes me wonder how many of its copyrights were transferred to APC. Logically, I would have to suppose a lot of that would depend on when APC acquired the company. I guess it's time to start seriously researching.