World history changed completely in the 11th century with two inventions: music notation was written on lines (staff), and solfege gave names to each note on the staff. Before, it took decades for a cantor to learn the music of the mass, and it could only be done orally. After, music could be printed and learned from books, at much greater speed. We could say that music literacy had a new birth. These two technologies: the 4-line staff, and solfege successfully helped singers for centuries. Why are we not using them anymore?

• instrumentalists preferred the 5-line staff, actually two 5-line staffs. Large polyphonic choruses too.
• the “scientific notation” giving a different name to 88 different notes (A3, A4, B4,…) matched the broader number of lines.

Singers had to adapt: learn this more complicated system, or find an instrumentalist to play the notes they had to sing. The latter is what how our catholic parish choirs learn to sing the mass… which is no more complex to sing now than it was in the 11th century.

In our 21st century, Square notation and solfege are still the simplest technologies to learn to sing the mass. They are the very epitome of the noble simplicity (knowable simplicity) required in the Roman Catholic liturgy. How?

A parish choir can learn the basics of solfege and square notation with a series of 3 x 90 minutes classes described at this link.

Then it takes practice:

Practicing solfege with chant – vocal and mental warm up

Practicing solfege with the Parish Book of Chant (dialogues and ordinary)

Practicing solfege with the Parish Book of Chant (Latin chant hymns)

Practicing solfege with the book of compline

Practicing solfege with a Catholic Book of Hymns

Learning to sight read can also start with singing the Liturgy of the hours:

Why Chant the psalms ?

Start chanting the psalms

A more specific example with singing Compline.