There are a number of mentions of Dolly (Dorothy) DYER in Blakeney area in the BNA from about 1913 to 1935. These make it clear she was a well-known organist in the area and was obviously in demand. There is also mention of a Kate DYER as an accompanist as well.
I wonder if she was part of this family. Arthur Edwin DYER was organist at Cheltenham College for many years and was followed in the same post by his son, Francis. The family seemed to be closely associated with music and teaching. If she had survived she would have been very old in the 1970s but I don't know the context of your query.
GR 1891 Census, Cheltenham, Bath Road, Malcolm Ghur
Arthur Edwin DYER, Head, Married, 48, Mus. Doc. Oxon, b. Somerset, Frome
Jessie Louisa, Wife, Married, 48, London, Chelsea
Kate Georgina, Daur, Single, 18, Somerset, Weston S Mare
Ada Frances May, Daur, Single, 17, Somerset Weston S Mare
Arthur Jas Leslie, Son, 15, Somerset, Weston S Mare
Francis Gilbert, Son, 14, Cheltenham
Herbert Arthur, Son, 13, Cheltenham
Dorothy Jessie, Daur, 11, Cheltenham
Winifred M. B, Daur, 9, Cheltenham
+ 2 servants
GR 1901 Census, Cheltenham, Bath Road, Malcolm Ghur
Arthur Edwin DYER, Head, M, 58, Music Doc, Organist, b. Somerset, Frome
Jessie Louisa, Wife, Married, 58, London, Chelsea
Kate, Daur, Single, 28, Headmistress, Somerset, Weston S Mare
Ada Frances, Daur, Single, 27, Assistant Sec. Ladies College, Somerset Weston S Mare
Winifred M, Daur, 19, Glouc, Cheltenham
+ visitor and 2 servants
GR 1911 Census,
Jessie Louisa DYER, Head, 68, Widow, Private means, b. Middlesex, Chelsea, London
Kate Georgina, Daur, 38, Single, Schoolmistress, Somerset. Weston S Mare
Francis Gilbert, Son, 34, Single, Schoolmaster ( Music Master), Glos, Cheltenham
Dorothy Jessie, Daur, 31, Single, Glos, Cheltenham