This site is in danger of going away; please consider the Donate link above...
To harp upon; to dwell upon a subject. Have among you, my blind harpers; an expression used in throwing or shooting at random among the crowd. Harp is also the Irish expression for woman, or tail, used in tossing up in Ireland: from Hibernia, being represented with a harp on the reverse of the copper coins of that country; for which it is, in hoisting the copper, i.e. tossing up, sometimes likewise called music.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Harmans * HarridanNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes
Buy a modern reprint of this book from Amazon CA; US;
Francis Grose was independently wealthy, having inherited money from his father, a jeweller. Finding himself overspending, he published a number of books; his Provincial Glossary seems to have been the starting-point for the Vulgar Tongue reproduced here.