Returning to the opening posting, the 'cock robin' song quoted by Graves is 'Robin Redbreast', published by Francis Day and Hunter in 1909 and sung by Harry Champion, who recorded it on the John Bull label in 1910. Kilgarriff, for once, is a touch misleading, listing two different 'Robin Redbreasts' (common enough name) under different headings, one of them an unrelated sentimental song by Claribel. I haven't checked, but he may have made the distinction clear later on his website. Kilgarriff remains the best starting point for anyone trying to track down a music hall song.