This quartet arrangement of Allegrasco was originally planned for clarinettist Roger Heaton and violinst Alexander Balanescu - two members of the Gavin Bryars Ensemble - to perform outside the context of the group. Allegrasco, which features solo clarinet with violin obligato, is a companion arrangement to that of ''The Old Tower of Löbenicht'' where the roles are reversed and the bass clarinet is an obbligato instrument to the solo violin. In both cases the additional instruments are piano and cello, giving the same instrumentation as Messiaen's ''Quartet for the End of Time''.