"Ode To Joy" was written in 1785 by the German poet, playwright and historian Friedrich Schiller. It celebrates the ideal of unity and brotherhood of all mankind.
This makes it a popular choice for weddings.
It is common to hear it as the postlude – or last song in a wedding ceremony. It is best known for its musical setting by Ludwig van Beethoven in the final movement of his Ninth Symphony. Completed in 1824, it is unique because it is a choral symphony for orchestra, four solo voices and choir.
You also may have heard it in some famous movies like Die Hard and Stanley Kubrick's A Clockwork Orange.
Beethoven's work became the official anthem of the European Union in 1972. The former anthem of Rhodesia used its tune.
The Symphony No. 9 in D minor, Op. 125 "Choral" is the final complete symphony of Ludwig van Beethoven. Completed in 1824, the symphony is one of the best known works of the Western classical repertoire. Critics consider it to be one of Beethoven's masterpieces and one of the greatest musical compositions ever written.
The symphony was the first example of a major composer using voices in a symphony. The words are sung during the final movement by four vocal soloists and a chorus. They were taken from the "Ode to Joy", a poem written by Friedrich Schiller in 1785 and revised in 1803, with additions made by the composer
Quoting from The Schiller Institute.org --
“Like the folk-tune which he had earlier adapted for the great choral finale of Fidelio, the melody is simple, adding to its popularity. By using such simple material and weaving it into higher and higher orders of complexity spanning the entire universe of human thought and feeling, Beethoven unfolded the message of human redemption which is implicit throughout Schiller's Ode to Joy, and carries us, together with the cherub at the climax of the finale, until we 'stand before God.'”
Joy, thou beauteous godly lighting,
Daughter of Elysium,
Fire drunken we are ent'ring
Heavenly, thy holy home!
Thy enchantments bind together,
What did custom's sword divide,*
Beggars are a prince's brother,*
Where thy gentle wings abide.
Be embrac'd, ye millions yonder!
Take this kiss throughout the world!
Brothers—o'er the stars unfurl'd
Must reside a loving father.
*Reworked by Schiller in the 1803 edition of his works to the more familiar:
What did custom stern divide;
Every man becomes a brother,
References: Wikipedia, The Schiller Institute