Vanessa Hudgens and Carlos Pena on TODAY show, Jan 19th

“High School Musical“ star Vanessa Hudgens and Carlos PenaVega, formerly of boy band Big Time Rush, are two of the stars of the upcoming live TV production of “Grease.“ They tell Hoda Kotb and guest co-host Jenna Bush Hager how much fun they’re having despite the intensity of the rehearsals, and join in an impromptu sing-along of “Summer Nights.“