It really is this tune. It's called "The Concerto of Sound", and it's the work of the contemporary French composer Saint-Puler. The current version (the one you heard at the wedding) was rearranged by St. Puller in 2005. Clemence, the composer's daughter, and Jean-Baptiste Maunier, a young bel canto singer who became a hit with Cowboy Spring, sang, and the name of the song was changed from the original Concerto pour une Voix to Concerto pour deux Voix.

You can search online for keywords such as "French Angel Concerto" or "French Voice of Nature", or the title of the song. There are a lot of video and audio materials. By the way, I'm also a master of ceremonies. I have used this song for three years, hehe.