2014 saw "Tale of the Brave" and Series 18, the second special and series animated by Arc, respectively. 2015 saw ', a special coinciding with the 70th anniversary of the franchise, and "Sodor's Legend of the Lost Treasure"; Series 19 began airing that same year. 2016 saw some changes; longtime composers Robert and Peter Hartshorne, father and son team, left the series and Chris Renshaw and Oliver Davis took over. 2016 also saw ' and Series 20 began airing the same year. Series 20 was the last series of the show to air on PBS Kids; when Series 21 began airing in 2017, the American broadcast of the show was moved to Nick Jr., ending a period of almost 28 years of "Thomas & Friends" on American public television. 2017 also saw . The show was pulled away from Nick Jr. at the end of 2019.