These fonds were largely created by Breandán Breathnach while he was chairman of the uilleann piping society, Na Píobairí Uilleann, from its establishment in 1968, right through the 1970s and into the early 1980s. The majority of the material dates from the decade 1968-1978. The first series contains letters from Francis O'Neill (O'Neill, Francis, 1848-1936) to William Halpin and letters from various individuals to Seán Reid (Reid, Seán, 1907-1978), mostly dating from the 1930s. It is most likely that the Seán Reid and Francis O'Neill letters were purchased by, or donated to, Breandán Breathnach in 1973 by Seán Reid after a request by Breathnach to deposit the originals in his newly established 'National Archives'. Breathnach wrote 'I am making so bold as to suggest you should donate these & other papers you might have to the National Archives new established in this Department or perhaps you would not mind offering them for sale' (M/187/3/3/2, 30 Oct 1973). These fonds also contain papers relating to Seán Ó Riada (Ó Riada, Seán, 1931-1971) from Len Clifford who seemed to be acting as an agent for ÓRiada during the early 1970s. It is not known how Breathnach came to be in possession of these papers, it is most likely that they were given to him as part of his national music archive project. The last series in this collection relates to the organisation Na Píobairí Uilleann. It includes correspondence and papers of a financial and administrative nature, as well as, documents relating to the organisation's various activities i.e. exhibitions, concerts, and pipe making.