 Amongst British composers , Sir Harrison Birtwistle readily acknowledges the influence of Stockhausen 's Zeitmaße ( especially on his two wind quintets , Refrains and Choruses and Five Distances ) and Gruppen on his work more generally ( Cross 2000 , 48 ; Cross 2001 ; Hall 1984 , 3 , 7 – 8 ; ( Hall 1998 , 99 , 108 ) ; ( Pace 1996 , 27 ) ) . Brian Ferneyhough says that , although the " technical and speculative innovations " of Klavierstücke I – IV , Kreuzspiel and Kontra @-@ Punkte escaped him on first encounter ( Ferneyhough 1988 ) , they nevertheless produced a " sharp emotion , the result of a beneficial shock engendered by their boldness " ( Ferneyhough 1988 ) and provided " an important source of motivation ( rather than of imitation ) for my own investigations " ( Ferneyhough 1988 ) . While still in school , he became fascinated upon hearing the British première of Gruppen , and 
