Using programs and tutorials online, it's not difficult to mathematically translate images into audio. When clever listeners use a spectrograph program or tool on the sound, it'll then reappear as a monochrome image. So what do you do with that audio file? Mix it into a song, of course. Twisted Sifter has made a reasonably exhaustive collection of spectrograms that appear in songs, most famously the Aphex Twin track known as "[Equation]" but also music from Nine Inch Nails and the Fez soundtrack.