Answer:
The entertainment of the Middle Ages developed into the entertainment of the Renaissance, which subsequently influenced everything that has come since.
In music, for example, there were several developments that were inventions of the Middle Ages that were later critical. One was the development of musical notation. Another was the development of bowed instruments similar to the violin. Another was the development of counterpoint, without which harmony probably would not have been developed, and music of today would have been entirely different.
In visual arts, perspective drawing was an invention of the Middle Ages, or a reinvention, to be precise, of something that had been known about in ancient times. Without it, the art of the period up to the twentieth century would have been entirely different.
In literature, the Middle Ages saw the development of vernacular written languages, a fact few people even think about today. This lead to the literature of great literature in the languages of the ordinary people. Our oldest, in English, is probably Beowulf, which is thought to date possibly from the eighth century, but possibly as late as the tenth. The Canterbury Tales, Chaucer's masterpiece, is medieval literature in a English. Without this sort of development, we would be learning Latin to read fiction or watch a play.