IMO it takes greater mental gymnastics to justify the current copyright laws which extend far past the life of the author than it does to justify a lyrics site. The current law is almost exactly what Jefferson was worried about when writing about US copyright in its initial form—it locks up vast swaths of modern culture and even that of nearly a century ago.

It's absolutely crucial to understand that law and "right" from an ethical standpoint are not necessarily the same, though that is the ideal state to strive for.