Bruno Walter, Friedrich Buxbaum, and Arnold Rosé were to perform Erich Korngold’s Piano Trio in D in 1910. Korngold was only 13 at the time.

These three great musicians were to remain Korngold’s devoted friends and admirers, and they frequently performed his subsequent works. Previous to this performance, Bruno Walter had known of the boy’s precocious gifts, not only through Gustav Mahler but also from having heard the child improvising for hours at a time from his flat above the Korngold family when they first moved to Vienna. Buxbaum, a lively, genial man and a brilliant cellist, became an especially close personal friend. 3 Arnold Rosé, who also knew of Korngold through Mahler, eventually gave possibly more Korngold premieres than any other musician. The concert was to take place on 11 December 1910, and young Korngold, together with his father and mother, was invited to the rehearsal. A much-told anecdote from this occasion sums up the relationship of the child to his domineering parents. Korngold sat down with his parents on either side of him. As soon as Bruno Walter began to play, Julius muttered, “Too fast,” whereas his wife muttered, “Too slow.” Indignantly, Julius Korngold repeated, “I say it is too fast,” while his wife countered with, “No, Julius it is too slow.” Their little son, who was, after all, the composer of the piece and presently sat squashed between them, interrupted, “I think the tempo is just right,” whereupon both parents turned on him and shouted in unison, “You shut up!” Whatever the disputes about the tempi, the performance was a great success.

Pauly, Reinhard (1997) A Biography of Erich Wolfgang Korngold. Portland, Or.: Amadeus Press, p.63.