“The earliest reference to a sing-out—the wild yell seamen would raise when hauling a rope hand-over-hand, a sort of embryo shanty—is to be found in a manuscript of the time of Henry VI, recording the passage in 1400 of a ship loaded with pilgrims towards the port of the shrine of St. James of Compostella….

>partial lyrics from Halliwell, as above<

...This in modern English would read something like:

Now the Old Man gives the order for the crowd,
To get to their stations (about the mast) and make sail,
'Haul away! Hoist 'er up! They cry,
'Hey mate, keep clear o' me!
Can't haul with you blowin' down me bleedin' neck!'
Croaked the older shellbacks.
A couple of deckboys climb aloft,
And overhaul the buntlines,
'Yo ho! Tail on the fall! the rest sing out,
And pull with all their beef.”
[Hugill foreword]