The concept of streaming digital music files over distances great (as with internet-streaming services like Spotify, Qobuz, Tidal, etc.) and small (from a home-PC hard drive, NAS, or networked music server) became mainstream only recently. But it was already brewing during the late 20th century, with people illegally downloading low-bitrate MP3 files made from CD rips and coming close to killing the recorded-music industry.