Music is increasingly recognised as important in facilitating healthy ageing, yet little is known of what musicians themselves learn when they teach older adults. This article reports the practices of the "Rhythm for Life" project at the Royal College of Music in the UK, in which conservatoire students taught 10-week programmes of group instrumental music lessons to adult beginners aged between 46 and 90 years. In order to interrogate what four student-teachers learned from their engagement with the project, qualitative data were collected through open-ended questionnaires, diaries and video-stimulated recall interviews. Findings demonstrated that the student-teachers reformulated the ways in which they thought about and taught older adult learners, and developed skills and knowledge relevant to a wide range of educational contexts. The article concludes that models similar to "Rhythm for Life", where conservatoires facilitate opportunities for students to teach older adults, may be an effective means of establishing meaningful learning experiences for music students and older adults alike.