The Canadian Barn Dance is one of the Scottish Ceilidh staples and good descriptions abound on the web. It's lively and straightforward, often called as a mixer (where you change partners and get to know everybody)
The setup is very much like the Chapelloise, you need a partner and you join in what should become a large circle on the dancefloor. You are side by side, facing anticlockwise round the circle and looking at the back of the heads of the couple in front of you. The men will be on the inside of the set and the ladies on the outside.
As it is a 'progressive' dance or 'mixer', you'll dance with your partner the first time through and then move on and dance with someone else. In this dance if the men snatch a look back over their right shoulder they'll see the lady they'll be dancing with next. As it's all in a circle, it's possible you'll get back to your original partner if the music goes on long enough.
If you were in a Scottish Ceilidh, you are likely to get a bright and crisp jig but it also works well to the same sort of schottischy tunes as Ideal Schottische and the Italian Polka It doesn't need to be hectic; a touch slinky allows you to make the most of the four steps of sliding apart and coming together again. With tunes of this persuasion, you do a Schottische step-hop, step-hop, step-hop, step-hop instead of the Polka.
There's a similar dance from Belgium called the Maclotte De Steinbach danced to the tune of the same name. The figures for this are: