A flock of seven white spheres powered by tiny propellers performed without a collision, or other hitch, at north London’s Roundhouse at the weekend. The inflatables took to the air and completed a mesmerising aerial display while dancers from the Royal Ballet and Company Wayne McGregor performed below. The human-meets-machine performance piece called +/-Human is the latest collaboration by the London- and Berlin-based artists Random International and McGregor, the resident choreographer at the Royal Ballet School. Dramatic lighting and atmospheric music by Warp Records help recapture something of the spirit of the late 1960s, when the railway shed in Camden was reinvented as an avant-garde arts centre. Happenings back in the day included Pink Floyd’s debut concert and light show. Unlike the ballet dancers, the spheres were soon back on stage to entertain the audience with an encore, performing faultlessly again, this time with young dancers from the Roundhouse Street Circus Collective, among others. The hard-working spheres take part in the installation Zoological, interacting with visitors in between dance performances (until 28 August). The human/machine experiment would hopefully have impressed Camden's most famous futurologist, H.G. Wells.