LIGNA is a radio collective exploring the aesthetic, social and political potential of radio. Based in Hamburg, LIGNA consists of the media theorists and radio artists Ole Frahm, Michael Honers and Torsten Michelsen. Since 1999, LIGNA started examining the meaning of dispersion in and of radio, relating to forgotten or isolated uses of this medium to developing new practices. LIGNA has put on performative radio plays, in which on-site broadcasts influence the process. Since 2002, LIGNA is developing concepts of how radio can intervene in public and often controlled spaces, so that their public reappears as an 'uncontrollable situation'.

LIGNA has been involved in AR1 in leading a workshop 'Models for Different Radio Usages' in Novi Sad with Kuda.org, and presenting their models for radio utilisation as part of the 'Uncontrollable Situations' exhibition in Belgrade.