 In the realm of contemporary or experimental classical music , the vocal melody for " Strawberry Fields Forever " is referenced as source material for the piano score of composer Alvin Lucier 's 1990 composition " Nothing is Real " in which the piano part , recorded in real time , is subsequently played back through a small speaker located within a teapot . Following instructions in the notated score , the pianist then raises and lowers the teapot lid , changing the acoustic filtering properties of the teapot as a resonator while attempting to filter specific frequencies as notated in the score . 
