Dasia Notation
An early-medieval tenth-century pitch notation system with its own signs for pitch, a forerunner of modern staff notation.
What it means
Dasia notation is a tenth-century pitch notation system named for the resemblance of its basic sign to the Greek spiritus asper, the dasia (Greek δασεῖα, "rough"). It ranks among the earliest attempts of the Latin Middle Ages to record pitch precisely and systematically in writing, making it an important forerunner of the staff notation developed later.
The notation is associated with the anonymous treatise Musica enchiriadis, one of the most important works of early medieval music theory.
In the notation
Dasia notation starts from four basic signs reminiscent of Greek instrumental notation. Through rotation and mirroring of these four signs, a system of eighteen distinct symbols emerged, capable of representing a complete tonal system of four tetrachords plus two additional pitches.