It all started back in September, when Robert Cass sent an e-mail to the staff telling us Billboard had announced that Chubby Checker’s “The Twist” is the top song of the Hot 100 era. The reactions were swift and predictably shocked, ranging from “There must not be a God” to “That is one brutal list” to “Just as a general rule, I don’t think an artist is allowed to complain about a lack of respect