Following the failed Hungarian revolution in 1956, he emigrated to Britain, arriving as a 26-year-old refugee speaking barely any English: all he possessed was his grandfather's overcoat, a letter of recommendation from Kodály and a box of conducting batons.
[7] He had founded the college's Kodály Choir in 1957 and commissioned the composer to create a cantata from Arthur O'Shaughnessy’s ode We are The Music Makers for Merton's 700th anniversary in 1964.
[1] As musical director at Merton, a post created for him, Heltay established in 1960 the Collegium Musicum Oxoniense choir, now the Schola Cantorum of Oxford.
[1][2][6][5] He gave the antipodean première of Britten's Albert Herring and claimed to have given Kiri Te Kanawa her first professional engagement before returning in 1967 to Britain to join Phoenix Opera as their conductor, with whom he worked for several seasons.
[1][2][6][5] In 1974, Neville Marriner encouraged Heltay to form the Chorus of the Academy of St Martin in the Fields,[2] composed of straight, accurate voices and designed to match the instrumental sound of the by then world-famous orchestra.
[2] In the 1990s, Heltay moved to Barcelona, where he served as director of the Spanish Radio and Television Choir from 1997[2][3] and continued a busy schedule of conducting and master classes for young choral conductors in Europe and the USA.