She began her studies as a pianist, but switched to violin at the Music Academy in Budapest when Jenő Hubay accepted her as a student. After concert tours of Europe and America as a soloist and chamber musician she settled in London. On memorable occasions, she and Béla Bartók gave sonata recitals together in London and Paris. His sonatas were dedicated to her sister Adila, but Jelly and Bartok presented them in London in March 1922 (no 1) and May 1923 (no 2).
She was an excellent interpreter of Classical, Romantic and modern music. Maurice Ravel dedicated his popular violin-and-piano composition "Tzigane" to her. Ralph Vaughan Williams dedicated his Concerto Academico to her. Gustav Holst's "Double Concerto for 2 violins" was written for Jelly and Adila. The D'Aranyi String Quartet is named after her.
She played a curious role in the emergence and 1937 world premiere of Robert Schumann's Violin Concerto. On the basis of messages she received at a 1933 seance, allegedly from Schumann himself, about this concerto of which she had never previously heard, she claimed the right to perform it publicly for the first time. That was not to be, but she did perform it at the London premiere. (Of this Robert Elkin remarked, 'of this dismal fiasco, the less said the better.')
While in her 20s, Jelly was a friend of Georgie Hyde Lees, later to become the wife of W B Yeats.
Jelly and Ravel
Jelly, Bartok and Ravel
Jelly and Georgie Hyde Lees
D'Aranyi String quartet
Jelly and Arthur Somervell
Jelly and Vaughan Williams
Jelly and Holst
Jelly and the discovery of Robert Schumann's Violin Concerto in D minor, WoO 23, through a seance
Photo of Jelly from 1933