As for any worship service, the music is to be chosen with care according to sound liturgical principles. A wedding is first a worship service - worship and praise to God who calls a man and a woman together. Music must express and deepen this worship of God for the mystery of love he created and transforms in this sacrament.
The following is a suggested list of wedding music. It is not an exhaustive list, but will give you an idea of what type of music is appropriate for a Catholic wedding liturgy.
Gathering Songs:
Responsorial Psalms: