In the passage, the author is primarily concerned with ______.

单项选择题According to the passage, John Coltrane did all of the following during his career EXCEPT ______.

单项选择题The author uses the example of the early models of high-speed railroad cars primarily to ______.

单项选择题In terms of its tone and form, the passage can best be characterized as ______.

单项选择题The author mentions the work of Ornette Coleman in the fourth paragraph in order to ______.

单项选择题The primary purpose of the passage is to ______.