A giant robot that predates Elbaf's legends? That means it was before the Void Century?!
Sommers over here reminding us (not that he needed to) that he's a celestial dragon by talking about how he likes listening to live performances, not because of the songs, but because he hopes someone messes up so he can shoot them, and considering how his devil fruit works... I can imagine that happening frequently.
Didn't expect Gunko to be a fan of Brook's music. Any other situation, I'd guess that Gunko would become smitten with Brook. However, considering that she's a Celestial Dragon, I'd guess that she would just rather keep him caged for as long as possible. Actually, thinking about it now, I don't believe Gunko was introduced with a family name like the other Celestial Dragons... meaning that she's probably not a genuine one and is only considered one through her affiliation with the God Knights, or her family name is to be considered a mystery for now.