Which play, produced in 1866, is often called the first modern musical?

The swing era began to decline after WWII.  When did the era begin?

A. in the early 1900s B. in the early 1910s C. in the early 1920s D. in the early 1930s

Turning the subject of a fugue upside down, or reversing the direction of each interval, is called ________.

A. inversion B. countersubject C. stretto D. retrograde