Complex sentence: The operetta premièred on 5 April 1874 at the Theater an der Wien in Vienna and has been part of the regular repertoire ever since: it appears as number 16 on the Operabase list of the most-performed operatic works.
Split into simpler sentences: The operetta premièred on 5 April 1874 at the Theater an der Wien in Vienna, and has been part of the regular operetta repertoire ever since. It appears as number 16 on the Operabase list of the most-performed operatic works.