Why is it necessary to learn Byzantine Notation?

Byzantine notation is the official notational system used by Byzantine cantors throughout the world. A cantor who can read neumes can chant along with colleagues from both the US and abroad and become a member of a Byzantine choir.
Every art has its own “tool box” and every language has its own alphabet. You cannot become proficient in Latin literature if you can’t read Latin. You cannot become a great opera singer if you can’t pronounce Italian, German, or other operatic languages. You cannot become a great Byzantine cantor if you can’t read Byzantine notation.
Western staff notation cannot capture certain nuances of Byzantine chant, including the overall shape of melodic formulae (theseis), microtonal intervals, and several qualitative elements.  A very small portion of chant has been transcribed into staff notation, thus limiting the repertoire of a cantor who cannot read Byzantine notation. Competency in the Byzantine notational system greatly expands the cantor’s access to the vast repertoire of Ecclesiastical music.

More information on this topic is available at the following link:  The Divine Music Project at St. Anthony’s Monastery