Manuscripts, mainly [19 cent., second ½]-1933, of the work of Welsh composers, mostly autograph, comprising holographs, copies and drafts of scores and sets of orchestral parts and also lyrics, including works by John Thomas (Pencerdd Gwalia), Dr Joseph Parry, David Jenkins, W. T. David and others. The collection also includes part of a Mass and a Te Deum by Giovanni Bononcini, 1747.

The records include catalogues of Welsh and English song titles with details of publishers, 1930s-1960s, and correspondence, 1957-61, with Messrs Lowe and Brydone (Printers) Ltd, concerning the printing of sheet music.