Olivia Newton-John, Alfonso Ribeiro, Janet Jackson join TODAY’s Halloween

02:29

The TODAY gang cut loose for a dance-themed Halloween, and some very special guests give them a big thumbs up. Olivia Newton-John offers advice to Savannah Guthrie about playing Sandy from “Grease”; Alfonso Ribeiro weighs in on Al Roker’s portrayal of Carlton from “The Fresh Prince of Bel-Air,” and none other than Janet Jackson pays tribute to Sheinelle Jones’ energetic impression of her!