So I Haven't seen any one mention the single most important piece of gear that totally changed how we listen to (and now) record music.
in 1965 a gentleman named James Russell invented the single most important piece of gear affectionately called the Compact Disk. however, the CD was not manufactured in mass until 1980 (the mass production of the CD enabled the beginning of the movement to hi-def recordings in the home).
Thanks to James Russel, we now have a great medium for storing and listening to music (and DATA).
The Compact disk lead the way for the DVD and Blue-ray medium.
If it wasn't for this digital medium, we would still be in the Analogue tape world.