Question 3: [6] By the early 1900s, the big trends in popular music were the increasing popularity of vaudeville theaters and dance halls and the new invention—the ________.
Question 6: "The most significant feature of the emergent popular music industry of the late 18th and early 19th centuries was the extent of its focus on the commodity form of ________" [6].
Question 9: One of the technological innovations that helped to spread popular music around the turn of the century was ________; these allowed people to hear the new popular piano tunes.
Question 10: Thus, for instance, ________ music continues to have a following, but it is probably a rather older group, on average, than the audience for rap[citation needed].