arts-and-culture, appreciating-opera, opera, aida, der-freischutz, die-fledermaus, fidelio, hansel-and-gretel, hms-pinafore, la-boheme, la-traviata, orpheus-in-the-underworld, the-barber-of-seville, the-child-and-the-spells, the-little-sweep, the-magic-flute, the-merry-widow, the-mikado, the-pirates-of-penzance, the-ring-of-the-nibelung, the-tales-of-hoffmann, secondary, lower-secondary, upper-secondary, adults, basic,