One of my friends shared this with me and I had to pass it on. It is an mp3 album from Amazon of "The 99 Most Essential Wedding Classics". Each song is $0.89 but the entire album is only $1.99. Most of the songs sound like they would be perfect for a ceremony.
ETA: I forgot the link!
http://www.amazon.com/99-Most-Essential-Wedding-Classics/dp/B004WV0FSU/ref=sr_1_72?t=slicinc-20&tag=slicinc-20&ie=UTF8&s=dmusic&qid=1303163946&sr=1-72