Also in the book "Tree of Strings [the harp] ["Crann nan teud" in Scottish Gaelic]: a history of the harp in Scotland" by Keith Sanger and Alison Kinnaird, Kinmor Music, 1992: is a warning not to confuse the Irishman "Rory Dall O'Cathain" with the Scotsman "Rory Dall MacMhuirich [Morison or Morrison]", the second being approximately a generation behind the first. According to the book, the Scottish Rory was a great musician but never composed original melodies. (Most of the blind ("dall") harpers lost their sight through smallpox in childhood. At least 7 of the 12 Belfast Festival harpers in 1792 were blind}.

The Irish "Rory Dall" is sometimes, wait for it, credited with composing "The Londonderry Air"!