Who begins the sampled beats on songs like 15 Step, The Gloaming, and 2+2=5? Is it Phil? Colin? Ed?

This is all regarding live versions obviously: That depends entirely upon the song, and what each member needs to do for that particular song. 15 Step is triggered by Colin and Jonny, although the main stuff is Colin. Colin also triggers the beats on 2+2=5 and The Gloaming, although the latter is mainly Jonny’s computer (Max). I can’t think of Ed ever triggering any beats, but Jonny also is responsible for the beat on Videotape, and for Idioteque although that’s less triggering and more synthesizing/controlling.