Will Hackett,
A song can be a cover of an original tune but have a completely different arrangement. You can pick any era of recorded music and find many covers of the same song. The cover doesn't even need to be in the same genre as the original. As an example https://www.youtube.com/watch?v=LGmQXuySF28 is The song "A Taste Of Honey" as an instrumental by Herb Albert and The Tijuana Brass and https://www.youtube.com/watch?v=MkQ1eOcl5ug the same song as sung by The Beatles. Eric Clapton made two versions of "Layla".
Unfortunately, not everyone is a musician, singer or have a desire to be an entertainer. But some non musicians do have musical ideas running through their head. Musical tools like DAWs, sequencers, soft synths, midi and audio loops and Band-in-a-Box gives everyone the opportunity to make, not just music, but good or excellent music.