That begs the question though, should it be? If you’re looking up the lyrics to a song you’ve bought, does it really matter, at least philosophically, how one retrieves them?
It shouldn't be. The idea that writing down the lyrics to a song and putting them on the internet for no financial gain at all should be punishable by some big record label is the kind of over zealous IP protection that 99% of HN users would have been against until something changed a few years ago and this place became a haven for copyright extremists.
The law here is no: If you own a copy of the song, you can reproduce the lyrics in whatever way you want.
What you can't do is distribute the lyrics without the author's permission.
When you ask DeepSeek to retrieve the lyrics (and it does so), the real question is this: Is DeepSeek merely acting as an intermediary/ISP according to the DMCA (in which case they'd be protected under the safe harbor clauses) or are they illegally redistributing the lyrics without the author's permission?
Whether or not you own a copy of the lyrics is irrelevant from a legal perspective in this scenario.
My guess: If they just retrieved the lyrics from some website and delivered them to you (because you asked), they're an ISP. However, if they pulled them out of their own database, they're violating copyright.