There's a letter printed in New York Times (22 September 1918) from an ex-sailor called William W. Urquart. As a youngster on his first voyage, sailing to France, the ship hit bad weather and the African American sailors aboard got in a huff because the cook had spoilt their food. Storm over, Urquart needed them to set the mainsail and topgallantsails. But they wouldn't sing, and it wasn't going well. In desperation he began to sing for them, "and made my debut in one of the chanteys I had heard them sing. As we were bound to France the song was rather Frenchy, and ran this way:

Boney was a warrior
Chorus - Whay aye aye yar,
Boney was a warrior
Chorus - John Francois

Boney went to Moscow
Chorus - Whay aye aye yar,
Boney went to Moscow
Chorus - John Francois

Boney never sulked they say
Chorus - Whay aye aye yar,
Boney never sulked a day
Chorus - John Francois,&.'

His improvisation amused the crew so much they stopped sulking. According to Urquart, black sailors 'were generally the best singers, and kept the best time.' He doesn't say when he began his career, but mentions working on the Black Ball line and appears to be the William W. Urquart (b. 1838 d.1920) listed in the 1910 census as living in New York. If so, he probably sailed first in the late 1850s?