Complex sentence: Most types of hurdy gurdy were essentially extinct by the early twentieth century, but a few have survived--the best-known of which are the French "vielle à roue", the Hungarian "tekerőlant", and the Spanish "zanfona".
Split into simpler sentences: Most types of hurdy gurdy were essentially extinct by the early twentieth century, but a few have survived. The best-known are the French "vielle à roue", the Hungarian "tekerőlant", and the Spanish "zanfona".