 Opera is frequently performed in Luxembourg City at the Grand Théâtre and in Esch-sur-Alzette at the Théâtre d’Esch as well as at the annual Wiltz festival.Luxembourg's internationally recognized soloists include violinist Sandrine Cantoreggi, cellist Françoise Groben, pianists Francesco Tristano Schlimé and Jean Muller, and singer Mariette Kemmer.Among its contemporary composers are Camille Kerger, Claude Lenners, Georges Lentz (although he lives mainly in Australia), Alexander Mullenbach and Marcel Wengler.