On our Youtube-Playlist you will find answers to this question in the form of interviews with Live Art protagonists and specialists..
#01Roger Hill
#02 Veronika Merklein
#03 Gabriella Cserhati
#04 Silvia Keller
#05 Katerina Kokkinos-Kennedy
#06 George Sachinis
#07 Lois Keidan
#08 Brian Lobel
#09 Vida Cerkvenik Bren
#10 Tuomas Laitinen
#11 Boris Nieslony
#12 Club Real
#13 Antoine Pickels
#14 Jeremy Smith
#15 Robert Pacity
#16 Deborah Hazler
#17 Aaron Wright
plus What is Live Art? from Joshua Sofaer
plus Frank Skinner on Performance Art | Unlock Art from Tate