I had just then [in 1947] finished research for my biography of Berlioz and had present in my mind a discrepancy between the French and the German editions of the score [for Romeo and Juliet]. They differed in the placing of mutes in the strings at one point in the Love Scene. I had mentioned this detail to Bruno Zirato, Caruso’s former secretary and now Toscanini’s Man Friday. To my surprise, I was invited to tea at the Villa Pauline, Toscanini’s house in Riverdale.
Toscanini questioned me closely as to the successive editions of the Berlioz score, the dates, the genesis of the work, the mood and intention of the passage affected, and the possible cause of the error in the score he had used [in the NBC orchestra performance of the symphony], which was the one edited in Germany forty years after Berlioz’s death. Then we talked about music in general, Berlioz’s instrumentation and harmonic practice, and finally he played for me a test pressing of the Queen Mab Scherzo from that same symphony. He stood close in front of me, listening intently and watching my facial expression at the delicate or difficult passages.
— Jacques Barzun, “Tocanini Then and Now,” Foreword to Mortimer H. Frank, Arturo Toscanini: the NBC Years (Amadeus Press, 2002).