translate English to French: The problem was explained, and he was asked to substitute for Michelangeli the next morning, on Friday, when the Toronto Symphony and the conductor, Karel Ancerl, were scheduled to work with Michelangeli.
On lui a expliqué le problème et on lui a demandé de remplacer Michelangeli le lendemain matin, soit le vendredi; alors que le Toronto Symphony Orchestra et son chef d'orchestre Karel Ancerl devaient pratiquer avec Michelangeli.