WHY!?!?!
It is soooo annoying to hear the beginning of an awesome song and have it cut off, because someone has finished their walk down the aisle.
Repetitive songs may be a slight exception if you plan and cue it just right (i.e. during a refrain skipping to the last part of the song so that no one notices that any of the song has been skipped).
When Justin and I were picking our music, I knew right away that I did not want the typical "Here Comes the Bride" song. We were not allowed to use pop music in the Catholic church, but we could use any classical song we wished. While I tend to get annoyed at the rules Catholics must follow, I was so glad that these restrictions were placed on the ceremony. It was clear from the Catholic music minister to the priest that the goal of the church was for us to have a beautiful wedding including a beautiful sermon (that was suppose to make the mom's cry, but it ended up making the dad's cry instead) and pretty music that wasn't too cheesy.
The music minister allowed us the option to choose any music he had available. He also gave us the option of having a family member sing a song approved by him and the church.
Either way, I think more brides should be mindful of what they choose to walk down the aisle to as well as the style of music played during the ceremony.