I know what a Neapolitan chord is and know how to use it in some usual ways. But I want to talk about the B♭ chord in C major. I think B♭ here is very "Subordinate". And we can see it always appears like (in C major):
B♭-G-C
B♭-F-G-C
etc.
My question is: Is B♭ chord related to the Neapolitan chord in A minor (the related minor of C major)?
The reason why I come out with this question is that, in modern popular music, the mode always changes between related major and minor (for example: C major and A minor)). In classical music, Neapolitan in A minor appears like: B♭/D-E7-Am (N6-d-t). So I guess that in modern popular music, people use Neapolitan chord in A minor to connect G and C (in C major) to blur the mode. But, I didn't find any evidence about this, that means B♭ in C major is nothing related to Neapolitan chord in A minor?