You will need to take a close look at the age groups of your guests. It is no good choosing 1 type of music and upsetting the rest of your guests.
You will need to choose a wedding march as well as some music for the church before the bride arrives. If you are having a choir or organist you can leave this up to their taste. However I have found some of the music to be inappropriate. For my wedding I drew up a list of my favourite love songs and had this played until my march. The music was relaxing and soothing whilst being meaningful.