She was born in Menai Bridge, Anglesey, the daughter of John Eilan Mason Parry and his wife Sarah.
[2] She was one of the first harpists in the UK to perform Ravel's Introduction and Allegro, at Bechstein Hall in 1913 under the composer's direction.
[4][5] On 15 December 1920 she played in the premiere of Arthur Bliss's Rout, for wordless soprano and chamber ensemble, at the London (Piccadilly) home of Baroness d'Erlanger, conducted by the composer.
[6] On 5 December 1942 Mason played in the first performance of Benjamin Britten's A Ceremony of Carols, for three-part treble voices and harp, in the library of Norwich Castle.
[9] Her star pupil at the academy was Osian Ellis (who succeeded her as Professor of Harp), but she also taught Gwendoline and Margaret Davies, Shân Emlyn Jones, Sheila Bromberg and Derek Bell of the Chieftains.