The La Scala production of La sonnambula in 1955 united three towering artistic personalities: Callas, Leonard Bernstein and Luchino Visconti. The excitement is palpable in this recording of its first night. Visually, it was of a stylised, Romantic beauty, with Callas presented like a classical ballerina. Aurally, Callas, supported at every turn by Bernstein’s alert and flexible conducting, portrays Bellini’s gentle heroine with exquisite empathy, creating a hushed, other-worldly atmosphere when Amina sings as she sleep-walks, and bursting with joy and relief in a blaze of coloratura in the opera’s final moments.