Manuscript and printed copies, 1905, 1948, of anthems, hymn-tunes and songs, composed or arranged by T. Osborne Roberts, including 'Berceuse' (ff. 8-10), 'I Loved a Lass' (ff. 32-35) and 'A Lullaby' (ff. 53-55), words by George Withers; 'Britain', words by John Ceiriog Hughes (Ceiriog) (ff. 16-17 verso); 'Seren fechan, Seren dlos' (f. 21 recto-verso) and 'Seren fechan yn y nos' (ff. 22-23 verso), words by Thomas Jones, Cerrigellgwm; 'Hiraeth' (ff. 30 recto-verso, 107 verso-108) and 'Y Mynydd' (ff. 78-81), words by Robert Williams Parry; 'The Kingfisher', words by William Henry Davies (ff. 38-40), and 'Y Lloer', words by W. H. Davies with a Welsh translation by R. Williams Parry (ff. 64-65); 'Medi' (ff. 58-61) and 'Y Wlad Annwyl Hon' (f. 133 recto-verso), words by Eliseus Williams (Eifion Wyn); 'Morfudd fy Mûn', words by Gerald Griffin translated into Welsh by Caradog Prichard (ff. 66-71 verso); 'Nefoedd', words by John Roberts (Ieuan Gwyllt) (ff. 82-90 verso); 'Stars of the Summer Night', words by Henry Wadsworth Longfellow (ff. 131-132 verso); and 'Ymson', words by Heinrich Heine translated into Welsh by Sir John Morris-Jones (ff. 134-141 verso).
Notes are added in the hand of Leila Mégane on ff. 138, 143, 150-158.

The vocal and instrumental parts, [c. 1925], of a setting by T. Osborne Roberts for solo voice and orchestra of 'Cymru Annwyl, Cymru Hardd', words by Lewis Davies Jones (Llew Tegid), together with a printed copy, 1925, of the work reduced for solo voice and key-board accompaniment.

The vocal and instrumental parts, [c. 1926], of a setting for solo voice and orchestra by T. Osborne Roberts of 'Min y Môr', words by Robert John Rowlands (Meuryn).

Manuscript and printed copies, [c. 1926]-1948, of Welsh airs and songs, arranged or composed by T. Osborne Roberts, including 'Acen y Glomen', words by Richard Davies (Mynyddog) (ff. 1-4 verso), 'Y Bwthyn Bach Tô Gwellt' (ff. 5-6 verso), 'Dafydd y Garreg Wen' (ff. 9-12), 'Melin Trefin', words by William Crwys Williams (Crwys) (ff. 13-14 verso), 'Hobed o Hilion', words by John Ceiriog Hughes (Ceiriog) (f. 22 recto-verso), 'Hwb i'r Galon' (ff. 28-29), 'Mae Nghariad i'n Fenws' (ff. 30-31), 'Pistyll y Llan' (ff. 36-39), 'Suo-Gân', words by Robert Bryan (ff. 40-44), and 'Trymder', words by Robert Davies (Bardd Nantglyn) (ff. 45-48).
Notes in the hand of Leila Mégane are added on ff. 32, 44 recto-verso.