History of "Danny Boy" is at www.standingstones.com/dannyboy.html
An ABC of "Londonderry Air" from George Petrie's original publication of it is on my website, along with some early versions of the related "Young Man's Dream" and the text of it and Ann Geddes Gilchrist's reconstructed "Londonderry Air". See Scarce Songs file at: www.erols.com/olsonw