Title: Ottoman Empire.
Question: What serviced as the foundation for the structure of the economy of the Ottoman empire?

Title: Frederic Chopin.
Question: What city did Chopin perform at on September 27?

Title: Gregorian calendar.
Question: What was the percentsge of correction from the Julian calendar to the new Gregorian calendar?

Title: Beyonce.
Question:
Totaling worldwide, how many records as Beyonce sold?