Alexei Ratmansky and American Ballet Theatre are a match made in ballet heaven. The artist in residence has a 10-year contract with ABT, and has choreographed abstract and narrative ballets for the company such as The Bright Stream, The Nutcracker and Firebird. At the Guggenheim’s Works & Process on Sunday, ballet mistress Nancy Raffa, and principal David Hallberg discussed what it's like to work with Ratmansky. Apparently, Ratmansky comes to the studio very prepared, with his 2x4 inch black book containing choreography to each count of the score.