Although you may not be familiar with the names of classical pieces, most are instantly recognisable when you hear them - though others are a little lesser-spotted. Talk to your ceremony singer or musicians about what classical piece you have in mind, and they'll likely be able to pull it out of the bag.
– Canon in D - Pachelbel
– Ave Verum Corpus - Mozart
– Bridal Chorus - Wagner
– Pie Jesu - adapted by Andrew Lloyd Webber
Classical Wedding Processional Songs