Free improvisation has two sources in the avant garde jazz, and experimental classical practices of the 1960s. Appeals to freedom, musical or otherwise, often result in more limitations. Sessions at Thames Valley University are managed by the students, and involve intense debate concerning how best to maximise collective musical freedom. Performances are triggered by individually prepared plans, which take the form of intervallic and rhythmic cells, registrally distinct roles, formal markers, dynamic processes, and even evocative poetics. Free collective improvisation in the classroom rewards sensitivity and sustained, intense concentration with a confrontational and convivial, ethical and musical, experience.