1922 Letter to Willem Mengelberg regarding possible engagement of Arturo Toscanini, as guest conductor of the Philharmonic; 1925 Correspondence regarding terms of engagement of Arturo Toscanini, as guest conductor in 1926; Trans-Atlantic Travel Plans; Newspaper Clippings in Italian Regarding Departure of Arturo Toscanini from La Scala, Milan; Correspondence on conflict between Arturo Toscanini and Benito Mussolini; ALS-Max T. Smith; ALS- Clarence Mackay; LS-Edward Erwin; LS-Anita Colombo; First Philharmonic Concerts by Arturo Toscanini, 1926; Agreement on terms for engagement of Arturo Toscanini for concerts in January and February 1926; Programs for concerts, Jan-Feb 1927; Program of Special Concert by Arturo Toscanini, 1 Feb 1926; Letter from Arturo Toscanini, 20 Aug 1925, stating terms for initial engagement as guest conductor