I took a survey course on the history of Western music, and I have decided to share the knowledge with Totse. I will do this by posting a new "Classical" music piece everyday for ten days. The pieces will be posted in chronological order, so you can see how the music develops.
Without further ado...
Day 1:
Title: Alleluia.
Composer: Hildegard von Bingen.
Year: ≈1150 AD.
Genre: Plainchant or Gregorian chant.
Style Period: Medieval.
Significance: The piece employs a nine note range, which was virtually unheard of at the time. Another important innovation of the piece is its usage of the leap of a fifth for dramatic effect.
Link: http://www.youtube.com/watch?v=27ol_QffDhE
Day 2:
Title: Gaude Maria virgo. .
Composer: The Notre Dame School.
Year: ≈1190 AD.
Genre: Organum.
Style Period: Medieval.
Significance: This is one of the first documented uses of polyphony.
Link: Couldn't find one.
Day 3:
Title: Ave Maria.
Composer: Josquin des Prez.
Year: Unknown.
Genre: Mass.
Style Period: Renaissance.
Significance: Josquin took polyphony to the next level - so much so that the music began to obscure the meaning of the lyrics, which was addressed by the Church during the counter-reformation.
Link: http://www.youtube.com/watch?v=LUAgAF4Khmg