The use of smartphones in music education has been increasingly discussed worldwide. In Brazil, access to these devices has become more widespread and democratized. This study investigates the potential of DAW applications for smartphones in teaching music composition to young people in an extension course. The specific objectives were: to ascertain possibilities for using smartphones in music productions with the group of participants; to investigate the participants' perception of the skills acquired in the course for their composition practices; to analyze how the skills developed in using DAWs impact the participants' ability to perform various roles, such as composers, producers, and arrangers; and to understand whether the specific functionalities of DAWs on smartphones contribute to musical experimentation and the creation of an environment for developing musical skills to compose anywhere and at any time. The methodology employed was action research (Tripp, 2005). A music composition course using smartphones was conducted with four young women over 12 meetings. Data collection included video recordings of the meetings, written reports, real-time notes and observations, virtual bulletin boards, audio recordings, and semi-structured interviews. The composition process developed gradually in layered instrumental tracks, following a top-lining model described by Bell, Cacho, and Okasha (2023), based on Bennett (2012). During the course, participants experimented with music, making decisions through audiation, selecting timbres and effects, composing for instruments they did not play, and releasing their first original songs. The DAWs used—BandLab and Zentracker—enabled simplified learning of musical concepts such as scales, chords, form, and structure, supported by instant visual and auditory feedback as well as undo and redo functions. Participants reported increased confidence in composing and the maturation of listening skills. As highlighted by several authors (e.g., Moorefield, 2005; Bell, 2018; King, 2018; Pendergast, 2021), contemporary DAWs blur traditional musical roles, allowing one individual to act simultaneously as performer, composer, arranger, producer, and engineer (Walzer, 2020). This phenomenon has led to the emergence of ‘hyphenated musicians’ (Pendergast, 2021), whose skills defy conventional categorizations. The use of DAWs on smartphones further emphasizes portability and the democratization of the studio, conceived as a symbolic space that can be present anywhere, stored online (Waldron, 2017), or literally in one’s pocket, and shaped by social and cultural factors. Future research could explore teaching composition with smartphones using other applications or DAWs, examine diverse audiences with larger participant groups, and investigate the integration of artificial intelligence in music education.