NEW YORK – Pretty much everyone on stage at the Metropolitan Opera in New York must audition – even the snake who will briefly take centre stage in an upcoming adaptation of a Mozart classic. In charge of deciding who gets the s-s-s-s-starring reptilian role is Zoe Ziegfeld, a carnival performer-turned-opera actor cast as the snake handler in the Met's version of Cosi fan tutte, inspired by Coney Island in the 1950s. Ziegfeld takes each snake, lets it slither and wrap around, then hoists the animal over their head, rehearsing what they will do under the bright lights at centre stage for each performance. Ziegfeld looks each one in the eye,…