Stheno is inspired by the oldest of the gorgons, monstrous characters of Greek mythology. The use of inside-the-piano extended techniques is constant throughout the work. Part of the musical material is obtained (as in Imaginary continuum) through the mapping of numerical sequences. Psychoacoustics (the scientific study of sound perception) is also very present in this Metaludio: textures that combine registers, intervals, and dynamics are often used to create new sonorities. Stheno is dedicated to pianist Miguel Ituarte.