fɚðə nˈaɪntiːnhˈʌndɹɪd fˈɪfti sˈɛvən ˈeɪksˈɛnpɹɑːvˈɑ̃s fˈɛstɪvəl, hiː ɹˈoʊt ɐ piˈænoʊ kəntʃˈɛɹɾoʊ, bˌʌt wˈʌn wˈaɪdɚ ɹˌɛkəɡnˈɪʃən fɚðə pɹəmˈɪɹ, kəndˈʌktᵻd baɪ lˈɛnɚd bˈɜːnstaɪn, ʌv twˈɛnti fˈoːɹ pɹˈeɪluːdz pˈoːɹ ˈɔːɹkᵻstɚ nˈaɪntiːnhˈʌndɹɪd fˈɪfti ˈeɪt.
For the 1957 Aix-en-Provence Festival, he wrote a piano concerto, but won wider recognition for the premiere, conducted by Leonard Bernstein, of 24 Préludes pour Orchestre (1958).