Select a number of items, press SHIFT and select any rotation

In order to keep items in a fixed composition while rotating all, the items now need to be grouped first. Otherwise each item will be rotated on its own and thus the composition gets lost. SHIFT is the key to group items, so it would be quite obvious to hold the SHIFT key while selecting a rotation for the selection of the items, without having to group these first, then rotate the group and finally ungroup all.