Ubiquitous music is a relatively new research area which seeks ways to involve novices in music learning, playing and improvisation. Despite the ambitious goals, ubiquitous music is still unknown territory in schools. In this study, we have tried to identify whether ubiquitous music environments can enable novice music students to participate in meaningful learning activities in a short period of time inside the school classroom. The proposed approach, named ImproviSchool, consists of two basic elements: a) a set of tangible music interfaces, and b) a fairy tale for which the students are asked to compose a soundtrack. The fairy tale is broken down into smaller episodes and for each one, the students are asked to compose a music score and dramatize the narration. At the end, students have to perform their creations in front of an audience. The whole process is aimed to last only two sessions of 2 school hours. ImproviSchool was applied in two 4th grade school classrooms of 15 students each, with the aim of evaluating both the set of the music tangible interfaces and the instructional approach. Data were collected through questionnaires and focus groups with the students as well as an interview with the music teacher. Students found the "music images" for playing and composing music easy, attractive, expressive, and enjoyable, and within a very short time frame, they created their own musical arrangements. Students showed enthusiastic with what they had produced and with their performance while at the same time achieving music learning objectives regarding instrument recognition, rhythm, pitch, volume and execution style. The realization of such a demanding activity in just 2 sessions shows that ubiquitous music can radically change the way in which musical learning evolves in schools.