The song was written by Catholics in England as a catechism song to teach their children
about the Christian faith. The song's "gifts" help remember the teachings of the faith.
"True Love" refers to God.
"Me" refers to every Christian.
The other symbols mean the following:
1 Partridge in a Pear Tree = Jesus Christ
2 Turtle Doves = The Old & New Testaments
3 French Hens = Faith, Hope and Charity or the Father, Son and Holy Spirit Trinity
4 Calling Birds = The Four Gospels
5 Golden Rings = First Five Books of the Old Testament
6 Geese-A-Laying = The Six Days of Creation
7 Swans-A-Swimming = The Seven Gifts of the Holy Spirit (I Corinthians 12:8-10)
8 Maids-A-Milking = The Eight Beatitudes (Matthew 5:3-10)
9 Ladies Dancing = The Nine Fruits of the Holy Spirit (Galatians 5:22-23)
10 Lords-A-Leaping = The Ten Commandments (Exodus 20)
11 Pipers Piping = Eleven Apostles, not Judas
12 Drummers Drumming = The Twelve Points of Doctrine in the Apostle's Creed