“Beethoven”, “Sonatas”, “E-flat”, in that order, were the first terms that came to mind for Susanne Kessel’s piece (250 piano pieces for Beethoven). Beethoven wrote four sonatas in E-flat major. 47 harmonically selected excerpts of varying lengths from these four sonatas – Nos. 4, 13, 18 and 26 – constitute the sound material for the resulting piece quarantasette estratti da un vicolo ludofilo or “forty-seven excerpts from a playful alley” («ludo» and «vico» yield the Italian form «ludovico» of “Ludwig”, «es» is German for Eflat).

The two-part piece – one part slow, one fast – of about two minutes is characterized by successive harmonically dovetailed links: the end of each excerpt harmonizes with the usually overlapping start of the next. At the end, the final bars of all four sonata movements sound simultaneously.