State Department records and traveler reports from 1958-1959 USA-USSR composer exchange under Lacy-Zarubin Agreement

I am preparing historiographical and musicological research on the American composer Roy Harris (1898-1979). I am in contact with the LoC regarding is Papers collection there, but there is a particular record about which the LoC staff recommends I reach out to NARA. Of particular interest at the moment are Harris's trips to the USSR. This first of these occurred in 1958 in connection with the then-recent Lacy-Zarubin Agreement. Emily Abrams Ansari's 2014 article for The Musical Quarterly (doi:10.1093/musqtl/gdu006) indicates a number of potential resources. The New York Times's Nov. 13, 1958, "4 Composers Tell of Trip to Russia" states that the composers (Harris, along with colleagues Peter Mennin, Roger Sessions, and Ulysses Kay) "made official reports to Washington," but I have not seen a reference for these. Where should I look? Of additional interest are federal documents related the reciprocal visit of Soviet composers in November 1959. This visit is mentioned in advance, for example, in the Department of State Bulletin from Nov. 2, 1959. Are there federal reports on this trip that might be available at the National Archives?