Integral aspect of popular culture? Not in America. Many people know "Drunken Sailor," but they don't necessarily file it into a familiar body of songs they'd know as "shanties."

Zappa's quote shows that these songs were *not* familiar to people in his general sphere (generation, time, location, etc). He was stretching beyond something, or at least felt like he did, to "discover" these "two old guys." If everyone were familiar with this repertoire we wouldn't have painted it as so "unlikely" or exotic.

In America, so far as chanties are known by people who are not hardcore fans of the genre, they are typically known as something "British" (and/or Irish) and rather exotic, obscure, "old", queer, etc. As such Americans (again, by which I mean general listeners) usually cannot have this concept of shanties as something "out there", "all around us", "a part of our common heritage", or whatever. It's a very different feeling of the self in relation to the genre than what I've seen many Britishers and Irish have. For Zappa, the music of these "two old guys" wasn't a satisfying part of his cultural identity (like "ah, me dad loved him some shanties as did me grandad before, and it always brings a wee tear to me eye when I hear one"...OK, I am being silly); it was something "wacky" -- wacky was what Zappa was about.

Yes, Zappa loved shanties in passing, but not because shanties were all about him and beloved by everyone and inescapable, etc etc, rather because his ears were open and because this particular album was one among many albums of different genres that crossed his table at some point.