Hi Donald, so nice to see you here but then you'd be a great addition anywhere. Hope I'll be seeing more of you here. Don I have to differ with you here. I met George Herbert (master rigger & former Cape Horner in his youth, would now be in his mid-late 90's if he's still going) around 20 years ago. Aside from getting a some songs that were gems I asked him a couple of questions. Was there harmony when they sang shanties & did concertinas go to sea. He said that he always took his concertina with him along with his alto uke. In the tropics he was constantly trying to keep the squeeze box dry. He also said that there was a fair amount of harmony. He said that there were so many different voices, some good, some bad, that the harmony was almost natural & he added that, that didn't mean it sounded good either. Funny, you mention about what they'd sing to collectors. George wouldn't sing any bawdy lyrics or make any comments of a sexual nature in the presence of women but he had a store of stuff that he thought that he had to explain after he sang them, I guess he though that only sailors would understand it.
The recordings of the West Indian & Georgia Sea Island shanty singers had a well refined & defined harmony so much so that they gave names to the singer's parts. A basser would sing a bass response to the high tenor, almost like a second low lead then a chorus would come in, in harmony, usually high. The high harmony & high lead were the most common seeing that the higher ranges were heard better above the surrounding din & less air was needed than would be in low ranges thus conserving energy for the more important job, the labor. See you some place soon Don. Barry