From here:

A remarkable composition, written in 1806 and still avant-garde when it was finally published in 1825, is Benjamin Carr's Fantasia on the Air 'Gramachree'. The original tune by an unknown author was first published in 1787 and sung in various versions—"A Maid in Bedlam," "Molly Asthore" (or "Mailigh Mo Store," "Molly Bheag O!," "Molly My Treasure"), and "Grai My Chree!" ("Love of my Heart!")—in Ireland, Scotland and England. This pining song for a lost love by the banks of Banna was known from three settings done by Haydn. Another folk song called "The Ould Bog Hole" contains similar lyrics: "The pigs are in the mire, the cows are in the grass, a man without his love is no better than an ass... O gramachree, mavourneen could you fancy me, Arrah cushla mavourneen won't you marry me." Carr's Gramachree begins unfolds like a long improvisation. Gramachree's overall dynamic intensity and the density of its virtuosic gestures border on the Lisztian. But other elements of the piece are still rooted in the Classical period.