950 – 1050 Late Parallel Organum

963-92 Otto the Great, first Holy Roman Emperor

1050 Chanson de Roland

This is the generation of Guido d'Arezzo.

Monophony

Sequence

A more regular type of sequence came into style around 950, characterized by strict poetic meter, lines of more equal length and some rhyme. An example was the earliest sequence to remain in the liturgy, Victimae paschali laudes, the Easter sequence by Wipo of Burgundy (c.1000-c. 1050).

Polyphony

Parallel Organum

Parallel Organum	|-Latin----- chant—vox principalis
	|-Latin----- added—vox organalis

By the time of Guido d'Arezzo (c. 990-1050) only type 3 organum at the fourth with occursus, was permitted.  This is the type of organum that begins in unison, moves to the fourth and then returns to unison at the end.

Theory

Hexachord system

Guido d'Arezzo perfected a method of sight singing using six-note patterns (called hexachords) with a half step between the third and fourth steps set to the syllables "ut, re, mi, fa, sol, la." The hexachord on G was called durum or "hard" and the sign for the B was b quadrun or square b which evolved into the natural sign. The hexachord on F was called molle or "soft," and the sign for Bb was b rotundum or round b which evolved into the flat sign. The hexachord on C was called naturale.



Guido's hexachord:

Note	Durum	Naturale	Molle	Durum	Naturale	Molle	Durum
ee							la
dd						la	sol
cc						sol	fa
bb♮							mi
bbb						fa
aa					la	mi	re
g					sol	re	ut
f					fa	ut
e				la	mi
d			la	sol	re
c			sol	fa	ut
b♮				mi
bb			fa
a		la	mi	re
G		sol	re	ut
F		fa	ut
E	la	mi
D	sol	re
C	fa	ut
B	mi
A	re
GG	ut

An adjunct to the system was the Guidonian Hand which assigned each of the twenty notes (B and Bb count as one note) of the hexachord system to a joint on the left hand.

Staff

Guido was also first to describe a four line staff with letters (F, C, G) which served as clefs. This invention has served to precisely identify pitches down to the twenty-first century. His most important treatise was Micrologus (c. 1030)