There are a lot of Scottish Gaelic, and I'm sure Irish Gaelic Puirt-a-beul, which literally means Tunes of the Mouth.

These are songs, some of them actually make sense too, which are used with tunes for dancing. It was thought some of them come from the time when Scottish music, in the form of fiddles, pipes, etc was banned by their English overlords. Thus songs like this were created.

Some of them are availeble at http://www.geocities.com/Area51/Zone/6338/port_gae.html