Unless you fancy yourself an audiophile, you may not hear much of a difference when listening to the MP3 of a song compared to its uncompressed counterpart. But find a way to isolate everything that's lost in translation, and that difference becomes audibly and eerily real.
Ryan Maguire's project The Ghost in the MP3 does just that, highlighting the fragments of sound left behind when a high-fidelity version of Suzanne Vega's "Tom's Diner" is reduced to an iPhone-friendly chunklet. Maguire used a similar process for the visuals, capturing the difference between a full-quality version of the "Tom's Diner" music video and a compressed MP4.
The resulting artifacts are elegiac and spooky, pairing shapeshifting pixels with audio that makes the "satanic backmasking" supposedly found in songs like "Stairway to Heaven" sound friendly by comparison. Suzanne Vega's hushed vocals probably contribute to the digital haunted house vibe, but Maguire didn't choose the song for its atmosphere alone: used as a reference track during the development of the ubiquitous file-format, "Tom's Diner" is now known as the "mother of the MP3."