The ingredients for Covent Garden’s new Orphee et Eurydice make the mind boggle. Direction is shared between a choreographer (the Israeli Hofesh Shechter) and a house director (John Fulljames), with 115 people almost constantly on stage: Shechter’s dance company, the Monteverdi Choir and the English Baroque Soloists under John Eliot Gardiner’s direction, plus Amour (Amanda Forsythe), Orphee (Juan Diego Florez), and Eurydice (Lucy Crowe).