How would you characterize, describe or call the traveling folk (non classical or church) musicians in the Breton area in France during the 18th Century? What type of music would they play? Did they have a special connection with the other Celts?

The bombard is a very popular instrument from the Renaissance and before that evolved in Brittany. It's a noisy, difficult to tune double Reed that is still played there and immortalized as a rather obnoxious (and one of my favorite) organ stop. Squawky, noisy, skirling.

I did some reading and instrumentation-wise, Breton music shares a great many similarities with other forms of what is called Celtic music.