Last night Matthew played a short set at the Omega Boutique Opening in Costa Mesa. He performed Summer Rain, Still Got Tonight, Somewhere Over The Rainbow, Hey and My Name.All the pictures here—–Matthew Morrison sings for O.C. shoppersThe average South Coast Plaza visitor could be forgiven for ignoring the crooner in the fedora on Tuesday night. While the Costa Mesa mall attracts its share of celebrities, they’re usually there to shop, not sing.Not Matthew Morrison. The 32-year-old “Glee” and Broadway star serenaded an invited crowd of about 150 in the Costa Mesa shopping center’s Jewel Court, a domed space in front of Macy’s. The area was curtained off, but the uninvited could still watch from the second-floor balcony. A few shoppers could be seen strolling by, taking a casual look downward then doing an amazed double take when they realized who it was.Morrison and his quartet were on hand to help celebrate the opening of Omega Boutique, a high-end Swiss watch retailer. Earlier in the evening, guests were feted with champagne and canap