Concern has been expressed about the safety of various forms of grandstands when subjected to human loading, particularly loading which is synchronised and periodic as may occur at pop concerts. This paper gives details of the main results obtained from BRE full-scale tests on six retractable stands. The dynamic behaviour of the empty stands in terms of their natural frequencies, damping values and mode shapes are presented. The results from three stands monitored during pop or rock concerts are presented in terms of the peak accelerations and displacements obtained, and the changes in natural frequency and damping that occurred as the stand was loaded. This paper will be of interest to those engineers who are responsible for designing stands or for local authority licensing of stands. 8 pages.