The fourth piece of the BXR cycle was written for solo cello. It is a set of seven small miniatures in which different intepretative aspects are addressed with a clear orientation to speculation with different musical parameters.
The seven parts are:
I Variables
II Verticals
III Points
IV Static
V Polymorph
VI Horizontals
VII Explosions
Its premiere took place in 1997 by Adolfo Ruiz de Conejo on the occasion of a tribute concert for the centenary of Casa Parramón in Barcelona.