It all takes place one summer at a music camp where the children crawl out of their tents every morning and gather for the day's rehearsals. Of course, there will be a concert eventually, but the road there is lined with both passions and complications. The horn player has lost his best mouthpiece and no one wants to help him look for it, except the conductor's 7-year-old son Franz. The conductor himself is constantly waving his baton, but life cannot be controlled by it. With unique animation techniques and specially composed music, the film takes us on an exciting journey among French horns and thistles.