When tuning pianos, we are often required to produce wide, narrow, or pure intervals.
Wide and narrow intervals beat because they are not pure.
The farther from pure they are, the faster they beat.
See how good you are at analyzing the relationships between wide, narrow and pure intervals, relative beat speeds, and the relative frequencies of these interval notes.
You have 5 minutes to complete the 20 questions. Get at least 18 right to pass. Good luck.