The goal of copyright law, in the US (from the Constitution, Copyright Clause) was: To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries.

All earthly art is influenced or derived from previous art. Some is outright copied, then modified to produce something "new". Sometimes this is considered valid, but sometimes it's not. Either way, that is how art (which includes music) works.

But in the US (and other countries with similar corporate influences), copyright is used both to prevent derivative works and to control the consumption of the art.

I could give numerous examples, but with this HN audience I doubt it's necessary. We've all experienced some unreasonable negative related to copyright.

So circumventing copyright puts the ethical control back into our hands. Those who are thieves and freeloaders will always exist, but the rest of us will contribute to supporting the art that we consume - even if we download that art "illegally".