The Bridal March or Here Comes the Bride is from Wagner's opera Lohengrin.
The Wedding March (usually heard as the newly wed couple leave the church) is from Mendelssohn's opera A Midsummer Night's Dream.
I observed at my sister, Janee's wedding reception that older generations tend not to dance to the "new" (read 90's) songs that we all know and love. They will however dance to familiar classics, Unchained Melody, I'm a Believer, etc. While the young folk will dance to everything. So to get the older generations to dance (without the use of alcohol) play songs everyone agrees on.
