The accordion, particularly the button melodeon, was an important British folk and popular instrument from the mid-19th century on. Accordions were also sailors' instruments.
Roberts, who worked on sailing cargo wherries much of his life, was a fine melodeon player and a singer with a very varied repertory: a hilarious epic about a North Sea oilrig; "The Grey Hawk," of Renaissance origin; "The Foggy Dew" in an eastern English version; shanties and more.