This pilot study analyzed the learning activities of adult musicians during the composition of a new musical work through online collaboration. The participants interacted in a virtual environment using synchronous and asynchronous tools to develop the composition project. The study utilized a mixed method descriptive design through video observation of the participants' interactions during the online activities. In addition, individual semi-structured interviews were conducted with the participants after the learning sessions to analyze the method of work and the processes adopted. The findings showed that (1) the participants successfully completed the composing task in the virtual environment; (2) the following five learning activities were observed during the video recording analysis: experimenting, listening/evaluating, constructing, playing and technical issues; (3) the following two themes emerged from the semi-structured interview analysis: activities and processes. The results are discussed considering the educational implications of the processes activated during the activities.