The Mariinsky Ballet has claimed its contemporary credentials, writes Clement Crisp. “For the fourth Mariinsky Ballet Festival the ballet company made its best claim for a valid modernity in a post-Soviet age with stagings of three ballets by Frankfurt’s William Forsythe. I have been watching and loving the Kirov since its first appearances in the west in 1961. I recall few evenings more significant, more assertive of the troupe’s potential and its greatness, than this, and I salute the company’s artistry in Forsythe as a logical extension of its grand academic identity.”