For the service, there are generally four elements of a wedding ceremony that require music:
Pre-Service:  Background music played as guests arrive and are seated.
Processional:  Music to accompany the wedding party and bride as they proceed down the aisle to the altar.
Interludes:  Music that is played during non-speaking portions of the wedding service, e.g. candle lighting, communion, signing of the registry, etc.
Recessional:  Music played as the couple and wedding party leave the service.

Generally, Brian will choose the pre-service music from his repertoire of classical-style guitar pieces and is happy to choose all of the music, if desired.  Interlude music is not always required - you may want to discuss this with your officiant.

You are welcome to choose from the following list of traditional wedding repertoire (audio samples to the right):
 
Processional:
Bridal Chorus - Richard Wagner
Canon in D - Johann Pachelbel
Spanish Romance (Romanze) - Anonymous
Trumpet Voluntary - Jeremiah Clarke
Wedding March - Felix Mendelssohn
 
Recessional:
Jesu, Joy of Man's Desiring - Johann Sebastian Bach
Ode to Joy - Ludwig van Beethoven
Trumpet Voluntary - Jeremiah Clarke
Wedding March - Felix Mendelssohn
 
Interludes:
Canon in D - Johann Pachelbel
Etude in B Minor - Fernando Sor
From the New World - Antonin Dvořák
Gymnopedie No. 1 - Erik Satie
Jesu, Joy of Man's Desiring - Johann Sebastian Bach
Spanish Romance (Romanze) - Anonymous