Before the service
Guests will be arriving at the church or venue, waiting for the ceremony to begin. Some joyous music should be played at this point to signify the happiness of the occasion. Popular pieces include:

Ava Maria - F. Schubert
Ava Maria - J.S.Bach (Gound)
Canon in D - J. Pachelbel  
Sheep May Safely Graze - J.S. Bach
Humoresque - A. Dvorak
The Bird - J. Haydn

March-in
The length of the March-in varies a great deal and the music to be chosen depends greatly on that. Choose a song with a pace that works with the march as well. Typically, the first song from the following list is used, amongst others:

Bridal Chorus - R. Wagner  
Canon in D - J. Pachelbel  
Hornpipe from "Water Music"- G. Handel  
La Rejouissance from ‘The Fireworks Music’ - G. Handel
Jesu Joy of Man's Desiring - J.S. Bach  
Trumpet Voluntary - J. Clarke  
The Wedding March (jazz)  
The Wedding (Ave Maria) (jazz)  
What a Wonderful World (jazz)  

Signing of the register:
This is the moment when there is a bit of a void in the air, as everybody focuses on the table at which the signing takes place. A light and sweet music fills this emptiness nicely:

Salut D'Amour - E. Elgar (Classical)  
Salut D'Amour - E. Elgar (jazz)  
Air on the G-string - J.S. Bach

March-out
This is the moment when the crowd cheers and the music must be bright and lively to go with the big applause:

Wedding March - F. Mendelssohn  
Trumpet Voluntary - J. Clarke  
Arrival of the Queen of Sheba - G. Handel