On the subject of the bagpipes in the aftermath of Collodden, in both Scotland and Nova Scotia, John G. Gibson (Traditional Gaelic Bagpiping, 1745 - 1945, McGill-Queen's University Press/ National Museums of Scotland, 1998) is currently the best authority.  In chapter 2, The Roots of Jacobitism and the Disarming Act, Gibson convincingly demolishes the myth that the pipes were banned.  He demonstrates that neither the Disarming Act of 1746 nor the amendments to it of 1748 mention bagpipes or any other musical instrument (and quotes the entire text of both in appendices).  There are records of two pipers being tried for treason; James Campbell Macgrigor (transported), and James Reid (executed).  Gibson writes:

" Reid the piper was hanged three months and fourteen days after the Disarming Act of 1746 was promulgated on 1 August of that year.  His conviction had nothing whatever to do with the act.  He was being tried for treason, having been captured in Carlisle as one of that city's garrison.  It bears repeating that the act's mandate, where arms were concerned, involved a clearly specified area of Highland Scotland.  Moreover, while the terms of the act date to 1 August 1746 (politically) and 12 August 1746 (royal assent), application of the part of the act pertaining to arms did not begin in the limited area of Gaelic Scotland until the summer of 1748...
James Reid had been captured in December 1745 as one of the Jacobite occupiers of the English city of Carlisle. Humble piper though he probably was, he had been in active rebellion and went to his execution for that treasonous crime, not for contravening the Disarming Act.  However, the court at York ruled with the words that have distorted the history of piping for generations: that "no regiment ever marched without musical instruments such as drums, trumpets and the like; and that a highland regiment never marched without a piper; and therefore his bagpipe, in the eye of the law, was an instrument of war."  The harshness of the judge's decision in Reid's case has no doubt added to the confusion; after all, at least six Scottish officers who were left to garrison Carlisle when the Jacobite army retreated north to its final grave were reprieved after being found guilty of treason at their trials, and James Campbell Macgrigor was transported; what's more, the English jury at Reid's trial had recommended mercy.  In short, Reid was the victim of judicial inflexibility, outrage, and revenge.
Although it is nowhere stated, Reid's case has almost certainly been emphasized for another reason.  If he was an ordinary unlanded man (and it is all but certain that he was), then he faced the choice of drawing lots to see who should be tried for treason and who simply transported without standing before a judge (under the lot system one in twenty of the common folk were chosen to stand trial as traitors, while the other nineteen were transported).  As James Logan* hinted, if anyone considered that a trial might enable him to avoid both the death penalty and transportation it was surely the non-combatant piper and the impressed man**.  Reid's plea would appear the more pathetic (as it did to the jury) if he eschewed the chance of life in a foreign land by opting for trial rather than drawing a lot.
The proponents of the idea that the Reid case set a precedent for the Disarming Act enforcers erroneously link what was a post-rebellion trial in an English city for the capital crime of high treason with the application of a calculated, extremely explicit sixteen-page act of the British government that had nothing whatsoever to do with proscribing the Highland bagpipes and was not enforced until after the Treaty of Aix-la-Chapelle ended the duke of Cumberland's European war in 1748.  Not only is there no mention of bagpipes or bagpipers in the act but no pipers were convicted as such under any of the act's published stipulations.  The records of the northern circuit of the Justiciary Court for the period 1748-51, for example, show no apprehensions, trials, or convictions of pipers."

* In The Scottish Gaël (1831).

** "Two other pipers, Nicholas Carr and John Ballantine, were among the five who were tried at York and acquitted of treason.  Both successfully claimed to have been impressed (legally compelled to serve in the army).

Malcolm