In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Let me give you an example: what is the first event mentioned?, Context: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
The answer to this example can be: Russian Revolution
Here is why: This is a good example, and the Russian Revolution is the first event mentioned.

OK. solve this:
What class are the Estonian Song Festivals?, Context: The tradition of Estonian Song Festivals (Laulupidu) started at the height of the Estonian national awakening in 1869. Today, it is one of the largest amateur choral events in the world. In 2004, about 100,000 people participated in the Song Festival. Since 1928, the Tallinn Song Festival Grounds (Lauluväljak) have hosted the event every five years in July. The last festival took place in July 2014. In addition, Youth Song Festivals are also held every four or five years, the last of them in 2011, and the next is scheduled for 2017.
Answer:
world