Here is John Cage’s Imag­i­nary Land­scape No. 4, per­formed by the Mael­ström Per­cus­sion Ensemble: [audio:http://radioartnet.net/audio/2550.mp3] Writ­ten in 1951, Imag­i­nary Land­scape No. 4 is scored for twelve radios. Two per­form­ers “play” each radio, one dial­ing the fre­quency, the other chang­ing the vol­ume and tone. The work is notated con­ven­tion­ally, i.e. with…