Poppy and Branch discover that they are but one of six different Troll tribes scattered over six different lands devoted to six different kinds of music: Funk, Country, Techno, Classical, Pop and Rock. Their world is about to get a lot bigger and a whole lot louder. A member of hard-rock royalty, Queen Barb, aided by her father King Thrash, wants to destroy all other kinds of music to let rock reign supreme. With the fate of the world at stake, Poppy and Branch, along with their friends, set out to visit all the other lands to unify the Trolls in harmony against Barb, who's looking to upstage them all.
When the Queen of the Hard Rock Trolls tries to take over all the Troll kingdoms, Queen Poppy and her friends try different ways to save all the Trolls.