Notes were invented by a monk Bashny.Net

Familiar names of each musical scale - from "before" to "B" - in the XI century was coined Benedictine monk Guido D`Aretstso and designated the first syllables of the words of prayer to John the Baptist. It requested the preservation of power voice: "Give us clean mouth communication. John, so we can all bear witness to the power of his voice about the wonders of your acts »:

UT queant laxis
REsonare fibris
MIra gestorum
FAmuli tuorum
SOLve polluti
LAbii reatum
Sancte Ioannes.

The first note, "ut" changed its name to more harmonious "before" in the XVII century, the latter as "B", though not in full agreement with the first syllable of the holy name, but it's more convenient to sing.

To specify the desired pitch Guido used his left hand. The tips and joints of each finger meant a certain sound. This allowed him to show the choir, which notes to sing.

via factroom.ru