Complex sentence: Thurman scripted both street/Muppet scenes on "Sesame Street", working in both capacities, and many animated sketches, for the latter, beginning with the show's debut in 1969 until 2007.
Split into simpler sentences: Thurman scripted both street and Muppet scenes on "Sesame Street". He produced many animated sketches on Sesame Street beginning with the show's debut in 1969 and continuing until 2007.