In southern England I first came across the usage in the mid 70s after an absense of a few years from the folk scene.

Always a mix of dance and sone (normally 2 dances and a song spot) and just before the take off of English Country Music, mostly Irish influenced tunes.

I remember everybody laughing when EFDSS ran a "ceilidh" with no song or morris spots. Post that on eCeilidh and Mr Harris wouldn't understand the joke..