This story was originally published on The Conversation. It appears here under a Creative Commons license. Imagine Lady Gaga or Elton John teaching at an orphanage or homeless shelter, offering daily music lessons. That’s what took place at Venice’s four Ospedali Grandi, which were charitable institutions that took in the needy—including orphaned and foundling girls—from the 16th century to the turn of the 19th century. Remarkably, all four Ospedali hired some of the greatest musicians and composers of the time, such as Antonio Vivaldi and Nicola Porpora, to provide the…