Complex sentence: Coleman was the most famous exponent of what is today known as the Sligo fiddle style, which is fast and flamboyant, and heavily ornamented with fingered "rolls" and bowed triplets.
Split into simpler sentences: Coleman was the most famous exponent of what is today known as the Sligo style. The Sligo fiddle style is fast and flamboyant, heavily ornamented with fingered "rolls" and bowed triplets.