In the present study we investigate what problems adolescents in year-nine compulsory school face when trying to learn to play a song together, how they take on these, and how their teacher responds to these problems. The studied practice, where students are to form a band and learn to play a song together in music class, is an example of education modelled on more informal, or out-of-school, practices such as leisure-time band practice. Such remodeled educational practice highlights the question of how to understand teaching. Sociocultural theory provides the framework for the analysis of video observations from classrooms. The results are presented in two sections: first, a global mapping of all problems the eight groups (bands) faced during the project; second, an in-depth analysis of the processes of two of the groups in terms of the central problems they struggle with and how the teacher enters into and contributes to their learning. It is found that the students struggle with basic issues, such as how to start playing a song (together), and that in lack of teaching in response to these problems, the students are precluded from engaging in and experiencing more inherent matters of musical expression. This is particularly unfortunate since the latter being the teacher's stated intent of the project. In conclusion, this educational practice plays out as a lost opportunity to further a great interest in music in adolescents.