Over the past decades, ‘participation’ has evolved as a key concept in a multitude of practice fields and discursive arenas, ranging from diverse political and economic contexts, through academic research, education and social work, urban planning and design, to arts institutions and artistic projects. While participation originally is a political concept and practice, it has long set out as a ‘travelling concept’ (Bal 2002). This special issue focuses on its travels between three fields of practice: the city, the arts and qualitative empirical research. Each of these practice fields over the past decades has yielded distinct understandings, objectives and methods in respect to participations, yet they also increasingly intersect, overlap and fuse with each other within specific practice contexts. What is more, many of the individual actors engaging in these initiatives on behalf of the city – from temporary projects to long-term collaborations – are not situated in one practice field only. Along with Jana König and Elisabeth Scheffel we understand them as ‘double agents’ (König and Scheffel 2013: 272–3) or even ‘multiple agents’, with simultaneous entanglements and commitments in more than one practice field.