Consider downloading this App on your cell phone for every-day practice: Square Notes

After you master at least one Kyrie, one Sanctus and one Agnus Dei (start with USCCB’s “Jubilate Deo” Mass and De Angelis (Mass VIII) ), you are ready to tackle these longer pieces:

• Gloria of Mass VIII,
• Credo III
• Pater Noster (only sung by the congregation in the Ordinary Form)

Excerpts from “The Mass and the Saints” (Thomas Crean, OP) about Gloria in Excelsis (see Books, books, books,… )

St Robert Bellarmine: “Almost all agree that Pope St Telesphorus* first laid down that this be sung at Mass” (* martyred in the year 136 AD)

Strabo: “He ordained that it be said before the sacrifice, so that the mind of those present might be calmed by the beauty of this angelic song in preparation for such great holiness”