1987: Digital Audio Tape
In 1987, Sony introduced the DAT format, expected to be the death knell of ordinary cassettes, to replace analog tapes. Though offering a unique combination of digital audio quality and easy recording, DAT never quite took off.
While audio professionals and concert bootleg traders quickly adopted DAT, it was never popular among ordinary listeners: DAT recorders remained pricey, and CDs fulfilled most digital audio needs. Perhaps the DAT's more interesting legacy is that it prompted early efforts by the music industry to legislate against digital copying: then-Senator Al Gore's proposed bill would have mandated using an early form of DRM to prevent DAT machines from copying copyrighted music.