AFAIK, all Gale's sources for this book were whalers' log books. So I would take his statement "this song sings to" as a suggestion as how it might be done, rather than as an assertion as to how it was done.

Gale Huntington was a very interesting man; he was a singer, and an amateur folkloric historian. Many of his songs came from his wife's family; her father was (I believe) Welcome Tilton, sailor and singer, and Gale published a selection of his songs in an early edition of Northeast Folklore. Unfortunately for me, I can't seem to find my copy, but it includes a version of the Flying Cloud which Helen Schneyer (and I) recorded, as well as the now fairly-well-known New England version of Rolling Home.

My singing partner Tony and I met them a few times, once on Martha's Vineyard where they lived, and another when we shared the stage at a whale convention, 30+ years ago.