The Duchess of Cambridge opted for a new label to attend the opening of the musical '42nd Street' this evening.

The 'Embellished Tulle Midi Dress' is by Marchesa Notte, named after Italian socialite Marchesa Luisa Casati.

The honeycomb design dress features a 50's silhouette with cap sleeves and a rhinestone belt. It is described, "Marchesa Notte's tulle dress is detailed with tactile lattice and rosette motifs. Partially lined to create a sweetheart neckline, this fit-and-flare design has flexible boning and a defined bead and crystal-embellished waist. The full, layered skirt is reinforced along the hem to hold its voluminous shape."

It is available for £1,105/$1,375 at Net-A-Porter and Saks Fifth Avenue.

Kate also debuted some rather fun earrings tonight! These are Kate Spade's 'Pretty Pom Tassel Drop Earrings' in burgundy, available at Nordstrom for £78/$98. They are described, "Threads of silk, playfully tasseled and studded with sparkling charms, create elegant drop earrings that frame the face in vibrant color."

The other accessories also perfectly matched her look, with her burgundy Mulberry 'Bayswater' clutch and Gianvito Rossi 'Gianvito 105 Suede Pumps' available for £540/$675 at My Theresa. However Bluefly has them on sale in the same 'Bordeaux' colour as Kate's for £280/$350.