To commemorate the 40th anniversary of the Music Undergraduate Program of the Universidad Pedagógica Nacional (National Pedagogic University), two musical events were planned: an original work written for choir, soloists and symphonic band, and an opera for children.As a result, the cantata 'The Perpetual Repeater" has been created as an adaptation of a work named "50 Milions de Segons" (50 Millions of Seconds), staged by the CATANIA project of the Barcelona Servei Educatiu de L' Auditori.This work tells the story of those school teachers who, paradoxically enough repeat the same course year after year.After visiting L' Auditori of Barcelona to participate in the pedagogic musical