Music manuscripts, including arrangements of folk songs and popular and classical songs by named composers; concert programmes, 1924-1961; press-cuttings, [1930s]- [1980s], of her performances; press-cuttings relating to the Official Receiver, [1950s]-[1960s]; and notebooks of song lyrics.

Manuscript oratorios, operas, orchestral pieces, choruses, melodies and other musical compositions (including the four Welsh Airs arranged for choir and full orchestra premiered at the Crystal Palace, 1896); an autographed notebook containing solfa versions of Welsh melodies arranged for male voices, 1915; correspondence, 1934-1935, relating to the proposed publication of a memorial volume to Jenkins by nine of his contemporaries ('Er Cof am yr Athro David Jenkins Gan Naw o'i Gyfoedion'); music exercise books, 1877-1881, and a volume containing blacksmith's accounts, Trecastell, and particulars of payments to preachers, 1796-1810.

Holograph manuscript music for Welsh and English vocal works, [?1950s]-1964; songs, 1918-[?1963]; orchestral works, 1939-[c. 1943]; works for wind and strings, [1930s]-1962; works for strings, including quartets, [?1920s]-[?1946]; pianoforte quintets, quartets and trios, [1920s]-1944; works for violin and pianoforte, 1920-1949; and miscellaneous works, [c. 1920]-1958.

Notebook, music book; anthems, hymn-tunes and marches; miscellaneous songs (solos and four parts); miscellaneous music; published compositions and scrapbook of Evan Morgan ('Alaw Tydfil'), Merthyr Tydfil, mainly containing copies of hymn-tunes by various composers.

Letters from Jack Edwards in Cincinnati, Ohio, to his family, 1880-1887, relating family matters, his work and singing engagements and news of the Welsh community in Cincinnati; programme cards of various concerts and festivals, 1882-1885; music notebooks of Jack Edwards, Edward Edwards and others, [19th century]-[early 20th century]; account and memoranda books of Edward Edwards' bookselling and binding business, 1854-1895; correspondence of Edward and Jack Edwards, including some in Esperanto, mainly on musical and literary matters, 1881-1936; and other original manuscripts of Jack Edwards, [before 1942].

Works for organ, transposed from old notation into tonic sol-fa.

Papers of the Department of Music of the University of Wales, Aberystwyth, 1883-1986, including concert programmes, 1898-1988, posters for concerts, 1961-[c. 1983]; minute book of the UCW Aberystwyth Musical Club, 1920-1927; student record cards, 1922-1929; attendance registers, 1933-1981; staff notes and reports, 1951-1983; miscellaneous papers and correspondence relating to the Department, 1921-1984; minute book of the Aberystwyth Music Festival, 1925-1927; papers relating to Aberystwyth and Gregynog music festivals, 1922-1969; music manuscripts and facsimiles by individual composers, including Arthur Charles Edwards, Ian Parrott, and David Wynne, 1916-1982; miscellaneous music papers, 1883-1904; papers of Charles Clements, 1909-1973; and papers of Griff Williams and his wife, 1916-[1980s].

Musical manuscripts and personal papers of William Mathias, including manuscript and published scores, 1950-1994; personal correspondence, 1972-1992; lectures and articles by him, 1972-1991; reviews, programmes, press releases, newsletters and ephemera relating to his work and honours awarded to him, 1952-1994; and correspondence of Yvonne Mathias relating mainly to performances of her husband's work, 1987-1994.

The five items deposited in 1995 was incorporated to the present structure and given E2d, B14c, K11b, K11c, and J1d as reference numbers.

Two items deposited in 1998 was incorporated to the present structure and given I1b and K18b as reference numbers.

Two items deposited in 2005 was incorporated to the present structure and given I27a and I28a as reference numbers.

An additional box of William Mathias's music manuscripts were received as a donation in August 2006. These manuscripts have been introduced at the end of the present structure as a Sub-fonds, entitled 2006 Donation, in February 2016.

William Mathias Recordings including reel to reel tapes, video tapes and vinyl records donated in July 2015 has been transferred to The National Screen and Sound Archive of Wales.

Gohebiaeth 'Alaw Ddu', 1870-1904; copïau llawysgrif o'i gyfansoddiadau cerddorol, yn cynnwys alawganau, 1878-1901, anthemau,1875-1903, emynau,1865-1895, caneuon crefyddol,1875-1896, caneuon seciwlar, 1879-[c. 1900], a darnau cerddorfaol, 1889-1899; ac eitemau amrywiol, 1879-1894 = Correspondence of 'Alaw Ddu', 1870-1904; manuscripts of his musical compositions, comprising cantatas, 1878-1901, anthems, 1875-1903, hymns, 1865-1895, religious songs, 1875-1896, secular songs, 1870-[c. 1900], and orchestral pieces, 1889-1899; and miscellaneous items, 1879-1894.

Papurau, 1838-[1991], yn bennaf papurau personol a theuluol Eunice Bryn Williams, 1838-[1991], yn cynnwys darnau cerddoriaeth yn llaw Eunice Bryn Williams, 1954-[1980au]; nodiadau darlithoedd ar gerddoriaeth, [1940au-1980au]; papurau'n ymwneud â Chymdeithas Alawon Gwerin Cymru a Chymdeithas Cerdd Dant Cymru, [1950au-1980au], ac eisteddfodau, yn arbennig Eisteddfod yr Urdd, [1930au-1980au]; rhaglenni cyngherddau o gerddoriaeth Cymreig, 1939-1961; a gohebiaeth deuluol,1888-1961. = Papers, 1838-[1991], mainly personal and family papers of Eunice Bryn Williams, 1838-[1991], including music pieces in the handwriting of Eunice Bryn Williams, 1954-[1980s]; lecture notes on music, [1940s-1980s]; papers relating to Cymdeithas Alawon Gwerin Cymru and Cymdeithas Cerdd Dant Cymru, [1950s-1980s], and to eisteddfodau, especially Eisteddfod yr Urdd, [1930s-1980s]; concert programmes of Welsh music, 1939-1961; and family correspondence, 1888-1961.