"A long time ago" - but I think my impression was that Stan was more or less ad-libbing, and would have seen that as part of presenting the shanty in an "ideal" or rather "authentic" way. Something to help get the work done, rather than a performance.

Though with some of the capstan songs we recorded Stan was happy to have a squeeze box accompaniment, because they would also have been sung for sheer enjoyment as forebitters.

In the record notes Stan wrote "In the past a painful camouflage clouded (the songs), and operatic perfection in the singing killed the clarity of the words with over harmonization and full orchestras killing the full atmosphere." That was what he wanted to avoid in the recording.