20th century and beyond | English homework help

the modern style of 20th century and beyond.  How does this style of music differ from older classical style and how is it similar?  Based upon what you have learned this semester, how are the elements of the Broadway Musical – West Side Story used?  1.  Rhapsody in Blue ~  Gershwin2.  West Side Story, Excerpts, Act I  (The Dance at the gym, Tonight: Quintet) ~ Bernstein