An economic explanation:
The harder it is to gain access to cultural elements, the higher the quality of those elements will be consumed. On the flip side, if it is easy to access culture, people will prefer to consume shorter lower quality pieces of culture. In the middle ages, people had to travel long distances to view concerts, which were performed by live musicians. Thus, the fixed costs of consumption were very high. If you bothered to pay a huge amount of money and time, you might as well view a long complex opera or symphony. On the flip side, when fixed costs are as low as a Google search, people prefer short YouTube videos of cats doing cute things.