A well thought-out concept album was to be their first recorded release, the musicians of Percussion Under Construction had already decided before Corona.

The forced break in the first lockdown in March 2020 strengthened them in this decision - newly created works in this exceptional situation were to enter into correspondence with previously known ones. Thus, Prelude I, composed by ensemble member Martin Hennicke during this time, reflects the situation of the soloist left entirely to his own devices, while he revised his work L.A., begun earlier, to represent the particular consternation of the mega-metropolis.

The composition, consisting partly of field recordings of industrial plants, takes on a life of its own and continues to exist even without the temporarily invisible people. Works of the last decades partly sound in new versions, new ones were created especially for the situation of the only virtually connected actors - an impressive demonstration of different worlds of experience.