Kan ha diskan (roughly translated as call and response singing) is probably the most common type of Breton vocal music, and is the most typical style to accompany dance music. It has become perhaps the most integral part of the Breton roots revival, and was the first genre of Breton music to gain some mainstream success, both in Brittany and abroad.

The lead singer is the kaner, and the second singer is the diskaner. The kaner sings a phrase, and the diskaner sings the last few lines with the kaner, then repeats it alone until the same last few lines, when the kaner again joins in. The phrase's repetition is changed slightly in each execution. Kan ha diskan can be songs about any subject, but must meet one of a number of a meters used in folk dances, mostly line or round. Vocables, or nonsense syllables (typically tra la la la leh no), are sometimes used to drag out lines. Usually a kan ha diskan lasts from 5 to 20 minutes.