Arnold Schoenberg in Barcelona - the 1930's
from Arnold Schoenberg Letters, page 166:
I still think very often of the two marvellous concerts you [Anton Webern] conducted in Barcelona; there’s nothing that could be mentioned in one breath with that.
Arnold Schoenberg, and Erwin Stein (ed.), Arnold Schoenberg Letters (1964), p. 166. https://led.kmi.open.ac.uk/entity/lexp/1448983947243 accessed: 13 June, 2021
Letter from Arnold Schöenberg to Anton Webern, Berlin, 12 August 1932