Song copywrites depend on when it was published. Music pubished before 1978 has a 95 year copyright. Music published after 1978 has a copyright of the life of the oldest surviving author plus 70 years. Anything published before 1923 in in the public domain.
The copyright for a published song is different than the copyright for recorded music. The last time I dug around ASCAP and BM(C; I? don't recall), it was about 7 years. And the copyright for songs published before 1978 was not 95 years. I wrote and copyrighted music prior to '78, and I think it was 10 years, then the copyright office changed it to 7 years.