"WHY SHOULD NOT POOR FOLK? (Cad fath nach ndeinfadh na boicht?). AKA and see "Jackson's maid at the fair." Irish, Air (6/8 time). C Major. Standard. ABC. O'Sullivan (1983) points out the tune, from Bunting's 1840 collection, is really an extended version of "A ghaoith on nDeas," printed in Bunting's 1809 volume A General Collection of the Ancient Music of Ireland (pg. 37). A version of the tune appears as "Jackson's maid at the fair" in O'Farrell's Pocket Companion for the Irish or Union Pipes (Vol. 1, pg. 771), c. 1811.
Source for notated version: the Irish collector Edward Bunting noted the melody in 1792 from "the performance of an old man well known by the 'soubriquet' of 'Poor Folk,' who formerly perambulated the northern counties, playing on a tin fiddle." O'Sullivan/Bunting, 1983; No. 50, pgs. 79-80."