The commentary I have read this last week on this case seems to all take one side or the other and makes absolutist claims for either. There are certainly many

The commentary I have read this last week on this case seems to all take one side or the other and makes absolutist claims for either. There are certainly many such cases in copyright law where things are obvious and the result of a court case clear in advance to those knowledgable of copyright law. This is not one of those cases, it is more subtle. The work is derivative, but he claims it is not a copy that has been filtered with an algorithm, he hired an artist to recreate it pixel by pixel by hand. Thus it's like an impressionist painting of a realistic photo. A substantial difference. Is it fair use? Fair use looks at many things not just one. Given that it's transformative to comment on what is being done to the music as well, and it's a non-commercial project (income went to pay costs and remaining profit went to charitable something or another), it might be fair use. Or it might not. This would have to be resolved in court because it's an edge case. It's not cut and dried who would win this case.