Brio the Minstrel was one of the Minstrels following Cantus. Brio is a bespectacled Fraggle who plays the cymbals. According to puppeteer Terry Angus (as explained here), Brio is also the only female minstrel, conceived by Jocelyn Stevenson to balance the gender ratio.
She first appeared in the Fraggle Rock episode "The Minstrels."