Historical exam revision

Have been doing some revision before my historical studies exam next Monday (ahhhhhh 1 week left!) 

The topic we studied this year covered music from 1910s-2000s separated into 4 classes: Rethinking Originality, Continuing the Tradition, The Avant Garde, and Minimalism. 

Not all of the music we studied was my cup of tea, but there were a couple that attracted my attention. 
Rethinking Originality: Charles Ives' The Unanswered Question, and Henry Cowell's The Tides of Manaunaun.
Continuing the Tradition: Stravinsky's Symphony in Three Movements, Olivier Messiaen's Twenty Contemplations on the Infant Jesus, Prokofiev's Symphony no.5, and Britten's Abraham and Isaac.
The Avant Garde: Xenakis' Concret Ph, Ligeti's Etudes Book 1
Minimalism: Michael Gordon's Trance, Steve Reich's Come Out, Piano Phase, and Gorecki's Lerchenmusik.