Very Interesting.Cover songs have been around for quite a while- after all, Elvis Presley's ' Blue Suede Shoes' was a cover of Carl Perkins' earlier version.
Carl Perkins' version
Elvis version (1956)
Also interesting. According to Wiki, it's a Civil War song from 1861.The music for Love Me Tender was actually from an old song named Aura Lee (or something like that). The words are from Elvis, but the music isn't.
Here's a version from 1936. Frances Farmer - Aura Lee
And Elvis's Love Me Tender - 1956