You may not believe it, but there are actually a lot of a cappella groups out there! None of them seem to get radio play, but if you dig around you'll find them. I was digging around and found SONS OF PITCHES, a New York based singing group that unfortunately no longer exists. during the decade they were together they release three albums. Their second album, WITH A "P", from 2002, contains a track suitable for this site: Kiss the Girl from The Little Mermaid.
Rather than giving this track a serious treatment, Sons of Pitches has found a humorous way to make their version memorable. This humour is mainly provided by the back-up vocalists who sing funny lines and even squawk like birds! You'll be in for a surprise once you hit the middle of the song! Enjoy!