TripleS is the Erasmus+ project between schools in Croatia, Romania and Germany. In TripleS 10- to 12-year-olds explore ways to save the climate and creatively spread their knowledge in a song. In Unison via Sounds pupils get to know each other and their surroundings. They ask each other for videos which they sort, evaluate and use in a collaboratively created piece of music, shared in an online meeting. The music production is an exercise for the remainder of TripleS. Unison via Sounds is finished after students’ evaluation which will feed back into the course and content of TripleS.