Located in the Ostersbaum district of Wuppertal is an unusual complex of public stairways linking the upper parts of the town with the town centre down in the valley. These stairways are well used by the pedestrian public – as welcome short-cuts to work, school and shops. They are part and parcel of the industrial architecture of 19th century Germany.

As his contribution to the temporary art project 7 Treppen (7 Stairways) of the Elisabeth Montag Foundation in Bonn (curator: Ingrid Raschke-Stuwe), Horst Gläsker transformed in 2006 the hitherto extremely neglected Holstein Stairway into a "Stairway of Feelings", which he titled SCALA. 112 steps were painted in different colours, and 112 words – all of them having to do with feelings in some way or another – were allocated to the steps. The word on each of the steps can be read as one climbs the stairway. Users descending the stairway can enjoy the pure scale of colours. This combination of colours and words sets in motion a kind of poetical logic that opens up the senses and allows the user to see and appreciate the situation in a completely new light. The user's physical and emotional constitution quickly reveals itself as he climbs the steps. The stairway may thus be seen as a metaphor for human existence.

The residents both in the immediate neighbourhood of the stairway and in the surrounding district first responded with scepticism to the embellishment of the Holstein Stairway. The idea of spending public money on art met with considerable incomprehension and this attitude was openly expressed. However, as work on the project progressed, and not least through the on-the-spot presence of the artist and his team for weeks on end, the atmosphere gradually changed into approval, enthusiasm and even personal identification with the art project. When the temporary project finally came to an end, the colours and words were removed from the stairway, whereupon the local citizens formed an action group that collected enough signatures to convince the City of Wuppertal to have the staircase restored by the artist in 2008. Thus the citizens of Ostersbaum were able to rescue SCALA for themselves and for their local environment.