Don't say that the creation of a song is like a poem. Helen Keller once encountered this kind of thing, but everyone she used to believe in thought that she copied a poem by another famous writer, but Helen really wrote that poem without knowing it, but many people misunderstood her as a person who could do nothing and then wanted to be famous.
In this case, it is hard to say clearly, but there is no way, because the author did not plagiarize, but there is no real evidence to prove his innocence, and it is easy to be detained as a so-called dirty person who does not respect other people's labor achievements and steals other people's intellectual property rights. So this also tells us that when publishing new works, we should check whether there are similarities, otherwise there will be big problems.