Please help i suck at research. Worth 55 points please answer. Which countries/cultures were more prevalent or relevant during the 20th century music time period

including the octave, the answer would 8 notes in a major scale with one note being played twice. ex) c major scale includes: c, d, e, f, g, a, b, c

notice that c is played twice

however, if you were to ask me how many different notes are in a major scale- the answer would be 7.  

the music of the classical period was often written to be more accessible and enjoyable for all people, rather than just the wealthy. how does contemporary music reach all audiences instead of selected patrons? select a contemporary genre of music and discuss how it reaches varied audiences. be sure to identify your musical choice within your discussion.