The song 12 days of Christmas is popular, in fact a lot of people sing this (specially during some Noon Time Christmas Presentations) but the fact is, not so many really knows what it means so I came with some writings courtesy of the Salvation Army (Philippine Territory).

The first phrase "On the first day of Christmas my true love gave to me…" the "true love" mentioned in the song refers to God Himself. The "me" who receives the presents refers to every person who accepted God in their lives.

1st Day:
The partridge (flesh of either quail or grouse ) in a pear tree is Christ Jesus upon the Cross. In the song, Christ is symbolically represented as a mother partridge because she would feign injury to decoy a predator away from her nestlings. She is even willing to die for them. The tree is the symbol of the fall of the human race through the sin of Adam and Eve. It also the symbolizes its redemption by Jesus Christ on the tree of the Cross.

2nd Day:
The "two turtle doves" refers to the Old and New Testaments.

3rd Day:
The "three French hens" stand for faith, hope and love—the three gifts of the Spirit that abide

4th Day:
The "four calling birds" refers to the four evangelists who wrote the Gospels—Matthew, Mark, Luke and John—which sings the song of salvation through Jesus Christ.

5th Day:
The "five golden rings" represents the first five books of the Bible, also called the Jewish Torah: Genesis, Exodus, Leviticus, Numbers and Deuteronomy.

6th Day:
The "six geese a-laying" is the six days of creation.

7th Day:
The "seven swans a-swimming" refers to the seven gifts of the Holy Spirit: wisdom, understanding, counsel, fortitude, knowledge, piety and fear of the Lord.

8th Day:
The "eight maids a milking " reminded children of the eight beatitudes listed in the Sermon on the Mount.

9th Day:
The "nine ladies dancing" were the nine fruits of the Holy Spirit found in Galatians 5:22-23: love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self control.

10th Day:
The "ten lords a-leaping" represents the Ten Commandments

11th Day:
The "eleven pipers piping" refers to the eleven faithful apostles.

12th Day:
The ‘twelve drummers drumming" were the twelve points of belief expressed in the Apostles’ Creed: belief in God the Father, the Son and the Holy Spirit, that Jesus Christ was born of the Virgin Mary, made man, crucified, died and arose on the third day, that he sits at the right hand of the father and will come again, the resurrection of the dead and life everlasting.

So why right it that way? worst why do you have to sing it?

During the period 1558 to 1829 in England, people were prohibited by the law to practice their faith either in public or private.
"The Twelve Days of Christmas" was written in England as one of the "catechism songs" to help young people learn the basics of their faith. In short, it was a coded-message, a memory aid.

Since the song sounded like rhyming nonsense, young people could sing the song without fear of imprisonment. The authorities would not know that it was a religious song.

"The 12 Days of Christmas" is in a sense an allegory. Each of the items in the song represents something significant to teachings of faith. The hidden meaning of each gift was designed to help children learn their faith. The better acquainted one is with the Bible, the more these interpretations have significance.