Given the task definition, example input & output, solve the new input case.
In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
Example: Passage: Nearing London, Oliver encounters Jack Dawkins, a pickpocket more commonly known by the nickname the "Artful Dodger", and his sidekick, a boy of a humorous nature named Charley Bates, but Oliver's innocent and trusting nature fails to see any dishonesty in their actions. The Dodger provides Oliver with a free meal and tells him of a gentleman in London who will "give him lodgings for nothing, and never ask for change". Grateful for the unexpected assistance, Oliver follows the Dodger to the "old gentleman's" residence. In this way Oliver unwittingly falls in with an infamous Jewish criminal known as Fagin, the gentleman of whom the Artful Dodger spoke. Ensnared, Oliver lives with Fagin and his gang of juvenile pickpockets in their lair at Saffron Hill for some time, unaware of their criminal occupations. He believes they make wallets and handkerchiefs.
Output: Who believes Fagin's gang make wallets and handkerchiefs?.
This question is based on the following sentence in the passage "He believes they make wallets and handkerchiefs". It evaluates the understanding that the pronoun "he" refers to name "Oliver". You can ask questions like this one about most pronouns in a paragraph.

New input case for you: Passage: Over the years, Nielsen wrote the music for over 290 songs and hymns, most of them for verses and poems by well-known Danish authors such as N. F. S. Grundtvig, Ingemann, Poul Martin Møller, Adam Oehlenschläger and Jeppe Aakjær. In Denmark, many of them are still popular today both with adults and children. They are regarded as "the most representative part of the country's most representative composer's output". In 1906, Nielsen had explained the significance of such songs to his countrymen:With certain melodic inflections we Danes unavoidably think of the poems of, for example, Ingemann, Christian Winther or Drachmann, and we often seem to perceive the smell of Danish landscapes and rural images in our songs and music. But it is also clear that a foreigner, who knows neither our countryside, nor our painters, our poets, or our history in the same intimate way as we do ourselves, will be completely unable to grasp what it is that brings us to hear and tremble with sympathetic understanding.
Of great significance was Nielsen's contribution to the 1922 publication,  Folkehøjskolens Melodibog (The Folk High School Songbook), of which he was one of the editors together with Thomas Laub, Oluf Ring and Thorvald Aagaard. The book contained about 600 melodies, of which about 200 were composed by the editors, and was intended to provide a repertoire for communal singing, an integral part of Danish folk culture. The collection was extremely popular and became embedded in the Danish educational system. During the German occupation of Denmark in World War II, mass song gatherings, using these melodies, were part of Denmark's "spiritual re-armament", and after the war in 1945 Nielsen's contributions were characterised by one writer as "shining jewels in our treasure-chest of patriotic songs". This remains a significant factor in Danish assessment of the composer.
Output:
What major world event led to Denmark seeing the man who wrote over 290 songs as someone who created "shining jewels in our treasure chest"?