In the course of the 20th century, musical improvisation became strongly associated with emancipatory politics, as expressive freedom in music symbolised forms of societal, cultural, and political freedom more generally. In the 1960s, European improvisers distinguished their ‘free improvisation’ from jazz and other improvisatory music by calling it ‘non-idiomatic’, i.e. not drawing on previously existing musical styles. Although the genre of free improvisation has formed a unique space of transnational and intercultural musical collaboration, such a utopian understanding risks an erasure of actual forms of inequality and exclusion. After all, to draw on one’s own musical tradition inevitably means to play in a specific idiom. To what extent has this definition of freedom as non-idiomatic playing excluded the participation of musicians of colour?