Irish tenor Alfred, played by McKade Hogg, prison warden Frank, played by Ian Fundytus, and Rosalinde, played by Jana Holesworth, perform during a dress rehearsal of "Fledermaus - The Opera Ball" this week at Southminster United Church. The operetta, by Johann Strauss, is being presented by the U of L Opera Workshop along with the Lethbridge Symphony Orchestra and Vox Musica. Performances are set for tonight and Saturday at 8 p.m. with tickets available through the Lethbridge Symphony Orchestra.