Allan Kaprow worked as an artist and art theorist on the evolution of improvised forms of action art and in 1958 he coined the word “happening” for it. He realized more than 250 happenings, including Time Pieces for the project Aktionen der Avantgarde (ADA 1) (1973), which was organized by the Neuer Berliner Kunstverein. The video Time Pieces from the documentation was a coproduction with the Neuer Berliner Kunstverein, which realized Aktionen der Avantgarde together with the DAAD and the Berliner Festspiele. Influenced by conceptual art, ADA initiated various performances, actions, and happenings in public spaces in West Berlin over several days. In Time Pieces, we see the participants recording the noises of their pulses and breathing, listen to them, and exchange them with partners by telephone or face to face. The happening was intended as a way to explore corporeal processes and make them “audible,” by counting loudly or beating along with one’s pulse and deliberate panting. By playing back the sound recordings, one can “listen to” one’s own body or those of others. Using modern recording techniques, Kaprow doubled the physical space of perception. In a final stage direction, the participants breathed into a plastic bag that had been taped together and then closed it. The unique Berlin recording of the first performance of Time Pieces was digitally remastered on the occasion of the forty-year anniversary of the Video-Forum in 2011 and this new version has been part of the collection ever since.