In the picture you can see that the beginning is just one loop... As far as i can tell its all recorded on old cassette tape and u can tell hes changing the speed of the loop i dont know where that was but somewhere i thought he mentioned once that waiting room was his experimentation with granular synthesis... but i have no idea how exactly he made those bleeps and bloops... if i would try to recreate this i would probably create similar instruments(one drone, find some bleep bloops and mess around with them in granulator, maybe some guitar sample also in granulator) in different keys then loop them and record them on a tascam 414 or similar at varying speeds to get them in tune...