“The keleustes or hortator remigium, is by some considered as the Boatswain; his duty was to repeat the orders to the rowers , and to distribute their allowance to the Ship's Company…. The last Officer whom we shall notice, though several other professional names occur in antient writers, was the..., or Musician, who endeavoured both by his voice and skill on whatever instrument he performed, to cheer the spirits of the Rowers:

Acclivis malo mediis intersonat Orpheus
Remigiis, tantos que jubet neocire labores.
Statius, Theb. V. v. 343

Against the mast the tuneful Orpheus stands,
Plays to the weary'd rowers, and commands
The thought of toil away.”
[Memoirs of Navigation and Commerce from the Earliest Period, The Naval Chronicle, Vol.II, 1799, pp.186-187]