Only ET was invited inside Max Dubrow's sound check with the iconic rock band. The 13-year-old performed with the band for the first time exactly 10 years to the day since her uncle, Kevin Dubrow -- the band's former lead singer, passed away.
Find out what went into crafting the standout moment of the space adventure, and hear from RiRi herself which costume was her favorite. (Valerian is available digitally now and on Blu-ray and DVD on Nov. 21.)
The actress reprises her voice role as Aunt Cass in the new one-hour television movie, airing Monday, Nov. 20 at 8 p.m. ET/PT on Disney XD and Disney Channel. 'Big Hero 6: The Series' will launch in early 2018.