In Scotland the Gaelic harp died out earlier than in Ireland, so there is no equivalent to Edward Bunting, noting down tunes straight from the harpers. However right up to the end Irish harpers travelled in Scotland - among them Denis O'Hampsey and Patrick Byrne - so there is no need to assume any great divergence in style or repertory1.
Instead, harpers in Scotland seem to have passed on their music to other musicians, so that harp tunes survive in scores set for lute, fiddle, and maybe even pipes2.
The name Rory Dall (Blind Rory) was used to refer to two completely different people, Ruairí Dall Ó Catháin (Rory Dall O'Kane) (c.1570 - 1660), an Irish gentleman harper who spent much of his life in Scotland3, and Ruaidhri Mac Mhuirich (Roderick Morison) (c.1656 - 1713/4), harper and poet to the MacLeods at Dunvegan4. Many tunes are attributed to "Rory Dall", or have his name in the title, prompting much argument between the Scots and Irish over which one they belong to. I lean towards the Irish one, not least because the Scottish Rory Dall seems to have worked primarily as a poet and a number of his verses, set to pre-existing tunes, still survive.
A class of tune strongly associated with "Rory Dall" is the "port". Although the word originally meant "a tune", it came by the 17th century to refer to a specific type of harp tune. They are characterised by a number of features, most notably a rather vague overall melody, a formalised rising introduction which may be the remnants of a tuning prelude, and division into two unequal sections5.
Another tune form often found in these Scottish sources is the lament, Cumha in Gaelic. These grand formal pieces can share features with Ports, not least of which is that both are sometimes given with variations written out6.
Much has been made of the presence, in the Scottish sources, of harp tunes with variations. Of course, the formal music of the Great Highland Bagpipe7, played in a living tradition from the 17th Century to the present day, is entirely built around the working out of formal and complex variations on a tune. Many people have claimed that the pipes took over the music of the harp in Scotland, and the presence of similar variation forms on these harp tunes seems to support this.
However it is important to remember that the harp tune variations that do survive are almost all in fiddle settings, and it is possible that the variations were added by fiddlers8. Nonetheless, many of the variations do work quite well on the metal strings of the Gaelic harp.
Such variatons seem to survive exclusively in Scottish sources, as when variations appear in Irish sources such as Bunting's manuscripts, they are much more baroque and European in style, and are commonly attributed to a named composer such as Cornelius Lyons (c.1680 - 1750).
There are also some Scottish pieces that occupy a slightly ambiguous middle ground; they are constructed in sections that follow on from one another, but are not strictly variations of an initial tune9. We must be aware that the nature of the old harp variation system is still far from clear.