There is that sea song about the mermaid, but I can't remember the name. "On Friday morn when we set sail/We were not far from the land/When the captain he spied a lovely mermaid . . ." Can't remember all the words. The chorus is "And the ocean waves do roll/And the stormy winds do blow/And we poor sailors go skipping to the top/While the landlubbers lie down below, below, below/While the landlubbers lie down below."

There is the song that Stan Rogers sings, The Maid On The Shore, but I am not certain if she is a mermaid or a witch or just good at singing sailors to sleep. No mention is made of a fish body, but she puts them into a sleepy trance and makes her escape.