Mezue ahịrịokwu na-esonụ: Rostropovich gbara egwu na The Proms n'abalị nke 21 August 1968. Ya na ndị Soviet State Symphony Orchestra kụrụ egwu <unk> ọ bụ egwu mbụ nke ndị egwu ahụ na Proms. Usoro ihe omume ahụ gosipụtara Cello Concerto na B obere nke onye na-ede egwú Czech bụ Antonín Dvořák ma mee n'otu ụbọchị ahụ na Warsaw Pact
wakporo Czechoslovakia iji kwụsị Alexander Dubček's Prague Spring. Mgbe egwú ahụ gasịrị, bụ́ nke a kwara n'ike n'ike ma mee ihe ngosi tupu ya emee, ndị na-ege ntị nọ na Proms kelere òtù egwú ahụ na onye na-agụ egwú nanị ya. Rostropovich guzoro ma welie akara onye nduzi nke Dvořák dị ka ngosipụta nke ịdị n'otu maka ala nna onye dere ya na obodo Prague.