I mentioned in another thread that I played a 'pretty' version of "Crawdad Hole" on the piano as prelude music for the wedding of my niece. (and no one noticed what I was playing) "Froggy Went a Courtin'" might be fun at some point when you don't have to be too serious. "Longer" though not 'folk' is a pretty song for weddings and would sound very nice with a guitar accompaniment and would sound even better if you could find a woodwind instrument to take the trumpet solo that Dan Fogelberg had in his recording.