Question: Which American actor, screenwriter, director, producer, singer-songwriter and author sang this song from the 1971 movie "Willy Wonka & the Chocolate Factory" that was written by British composers Leslie Bricusse and Anthony Newley?
Sentence (from "Wonka Bar"): The Wonka Bar is both a fictional candy bar, introduced as a key story point in the 1964 novel "Charlie and the Chocolate Factory" by Roald Dahl, and a type of consumer product candy bar inspired by the fictional confection.
Relevant evidence: No