Hallberg's appearances at the Bolshoi and the Mariinsky (Kirov) theaters from 2008-2011 revealed him as a virtuoso dancer best suited for romantic parts. And lyrical dancers with impeccable technical skill are hard to come by. Filin was, and remains, one of the few.
It was Filin who invited his American colleague to work at the Bolshoi. Filin's predecessor, Alexei Ratmansky, had engaged Hallberg in his 2010 production of "The Nutcracker" at the ABT. And this year, Hallberg appeared as Prince Siegfried in "Swan Lake" at the Mariinsky Ballet Festival.